DHAKA, Bangladesh -- At least 20 people were killed Sunday and Monday in clashes in Bangladesh between police and hard-line Islamists demanding new laws that critics say would amount to the "Talibanization" of a country that maintains secularism as state policy.

Clashes began on Sunday after about 200,000 Islamist supporters marched toward Dhaka, the capital, to press their demands and were met by lines of police firing tear gas and rubber bullets.

AFP - Getty Images

Islamist protesters throw bricks and stones toward Bangladeshi police during clashes outside Dhaka on Monday. Since Sunday, at least 20 people have died as the hard-liners demand laws based on religion.

On Monday, hundreds of protesters, many wearing white Muslim skull caps and throwing stones, regrouped and police again fired tear gas, rubber bullets and water cannons to disperse them.

Violence spread from the capital, where at least 13 died. Five people were killed in Chittagong and another two in Bagerhat.

Protesters set fire to vehicles, including two police cars, and stormed a police post on the outskirts of the capital, police said.

Two policemen and a member of a paramilitary force were among the people killed on Monday, said police official Shah Mohammad Manzur Kader. Four people were killed on Sunday, and hundreds have been injured, hospital officials said.

The protests are led by a group called Hefajat-e-Islam, which set a May 5 deadline for the government to introduce a new blasphemy law, reinstate pledges to Allah in the constitution, ban women from mixing freely with men and make Islamic education mandatory.

Munir Uz Zaman / AFP - Getty Images

Islamist protesters gather Sunday on a highway at an entry point to the Bangladeshi capital, Dhaka, as they try to enforce a siege in demand of religious laws. The country has a secular government.

The government of the overwhelmingly Muslim country has rejected the demands.

The clash of ideologies could plunge Bangladesh into a cycle of violence as the two main political parties, locked in decades of mutual distrust, exploit the tension between secularists and Islamists ahead of elections that are due by next January.

Bangladesh has been rocked by protests and counter-protests since January, when a tribunal set up by the government to investigate abuses during a 1971 war of independence from Pakistan sentenced to death in absentia a leader of the main Muslim party, the Jamaat-e-Islami.

Jamaat opposed Bangladeshi independence from Pakistan in the war but denies accusations that some of its leaders committed murder, rape and torture during the conflict.

The Hefajat-e-Islam emerged from the protests over the tribunal.

More than 100 people have been killed in the clashes this year, most of them Islamist party activists and members of the security forces.

This story was originally published on Mon May 6, 2013 8:54 AM EDT

Shariah policemen speak to a student who was caught playing games in an Internet cafe during school hours in Banda Aceh, in Indonesia's Aceh province. The boy was given a morality lecture and forced onto a shariah patrol truck to be taken back to school, where he faced humiliation from other students and teachers.

Female members of the Wilayatul Hisbah shariah police get instructions from a commander before going on patrol in Banda Aceh.

Photos and text by Damir Sagolj, Reuters — Indonesia is the world's most populous Muslim nation, but nowhere is the faith more strictly interpreted than in Aceh, sometimes referred to as the "verandah of Mecca" because it was one of the first parts of the archipelago to turn to Islam. 

Aceh, which was hit by a tsunami in 2004 that killed an estimated 130,000 in the province, is Indonesia's only district to have implemented shariah, or Islamic law. This is something that occurred for complicated reasons, some of which go well beyond the religion itself and have more to do with Acehnese tradition, the long struggle for independence and conflict with outside forces, Jakarta included.

Hard-line Indonesian police shave punks' mohawks in 'moral rehab' drive

Formed to implement shariah law, Wilayatul Hisbah, which is the official name for the shariah police, is spread across the province working in small units, patrolling and conducting occasional raids. The units are made up of different kinds of people – some of them claim to be on a mission, others just needed a job.

The set of laws in force in Aceh is just a smaller part of what would be full shariah implementation, covering all levels of society. At present, the shariah package in Aceh targets only those violating the Muslim dress code, illicit behavior, drinking and gambling.

Shariah punishment for Indonesia coffee shop gambler

Dating can be particularly hazardous — under shariah, it is a crime for an unmarried man and woman who are not related by blood to associate in an "isolated place." As a consequence, it has become increasingly popular for young couples to get to know each other using social networks like Facebook. Read more at Reuters' Photographers Blog.

A shariah policeman shows dominoes found in the bag of a boy who ran away after a patrol spotted him and a friend during school hours in Banda Aceh. The dominoes were thrown in the mud and police continued their patrol after unsuccessfully chasing the boys.

A young couple chat in the shade on a beach near Banda Aceh. Under shariah, it is a crime for an unmarried man and woman who are not related by blood to associate in an "isolated place."

Members of the Wilayatul Hisbah speak to a young couple after they were caught sitting too close to each other in an isolated place in Banda Aceh.

Winda Wahyuni kisses the hand of her husband, Ahmad Yasir Saputra, after they got married in a mosque in Banda Aceh. Winda and Ahmad Yasir, who met a year ago on Facebook, married in a religious ceremony in a local mosque. Dating on social networks has become increasingly popular in Aceh due to the restrictions that shariah places on unmarried men and women.

Winda Wahyuni, center, and husband Ahmad Yasir Saputra, left, pray during their wedding ceremony in a mosque in Banda Aceh.

A man is seen from inside a house in Banda Aceh that was destroyed in the 2004 tsunami. Some residents near the sea believe the tsunami that killed an estimated 130,000 people in Aceh province was a punishment from God for those who broke Islamic laws, and they fear it might happen again.

Boys and girls meet at a cultural event in Banda Aceh.

Muslim worshippers gather for an evening collective prayer outside a mosque in Banda Aceh.

Acehnese Protestants attend an early Christmas mass in their church in Banda Aceh. Although it is complicated to build a new Christian church in the predominantly Muslim province, Father Amrin Sihotang of HKBP Protestant church said his community has no problems with strict Islamic laws as long "as we follow the rules."

Young people relax at Ulhee Ilhue beach in Banda Aceh. The gates of the beach close every day at 6 p.m. to prevent people violating Islamic law. Asked about shariah police who often patrol the beach looking for violators, one of the youngsters said, "I don't like them. They simply disturb me."

Female members of the Wilayatul Hisbah enter a public park as they search for those violating shariah law during their patrol in Banda Aceh.

A female member of the Wilayatul Hisbah insists on inspecting the clothes of girls relaxing in a park in Banda Aceh.

Members of a punk band named Trotoar Chaos are shown in Banda Aceh. Although they say they have been punished and had their hair shaved in the past by police, the young musicians remain defiant and insist they will stay in Aceh. One of them commented on a 2011 incident in which he was punished after being caught among 65 other punks at a concert: "There is a big change after that. Now I want to fight more."

A member of the Wilayatul Hisbah tells a man he should stop eating his lunch and go to the mosque just before Friday prayers in Banda Aceh. Besides patrolling with their male colleagues every day looking for those who violate shariah, female police officers drive through the town just before Friday prayers urging businesses to close and demanding that men go to pray.

A Muslim family enjoys nice weather on a beach in Banda Aceh.

EDITOR'S NOTE: Images taken between Dec. 6 and Dec. 11, 2012, and made available to NBC News today.

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Chaideer Mahyuddin / AFP - Getty Images

A group of punks are detained in Bandah Aceh police station in Aceh province, Indonesia, on Dec. 13, 2011. Sharia police are "morally rehabilitating" more than 60 young punk rock fans, saying the youths tarnish the province's staunch Islamic image.

The Associated Press reports from BANDA ACEH, Indonesia:

Police in Indonesia's most conservative province stripped away body piercings and buzzed off spiky mohawks from 65 youths detained at a punk-rock concert because of their perceived threats to Islamic values.

The teens and young men were also stripped of dog-collar necklaces and chains and then thrown in pools of water for "spiritual" cleansing, local police chief Iskandar Hasan said Wednesday.

After replacing their "disgusting" clothes, he handed each a toothbrush and barked "use it."

Chaideer Mahyuddin / AFP - Getty Images

Police escort the youths through the police school compound in Aceh Besar.

AP

Plain-clothed police officers shave the heads of the punks.

It was the latest effort by authorities to promote strict moral values in Aceh, the only province in this secular but predominantly Muslim nation of 240 million people to have imposed Islamic laws.

Punk rockers have complained for months about harassment, but Saturday's roundup at a concert attended by more than 100 people was by far the most dramatic.

Baton-wielding police broke up the concert, scattering young music lovers, many of whom had traveled from other parts of the sprawling archipelagic nation.

Dozens were loaded into vans and brought to a police detention center in the hills for rehabilitation, training in military-style discipline and religious classes, including Quran recitation.

They will be held there for at least 10 days, after which they'll be returned to their parents.

Chaideer Mahyuddin / AFP - Getty Images

A youth grimaces as his spiky mohawk — deemed insulting to Islamic traditions — is buzzed off.

Twenty-year-old punk, Fauzan, was mortified.

"Why? Why my hair?!" he said, pointing to his cleanly shaven head. "We didn't hurt anyone. This is how we've chosen to express ourselves. Why are they treating us like criminals?" Read the full story.

AP

After being shorn of their locks, the youths were thrown in pools of water for "spiritual" cleansing.

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