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US citizen slain in Afghan suicide attacks

A suicide bomber struck a crowd of Shiite worshippers who packed a Kabul, Afghanistan mosque Tuesday to mark a holy day, killing at least 56 people, and a second bombing in another city killed four more Shiites. NBC's Atia Abawi reports from Kabul.

An American was among those killed in a series of deadly attacks Tuesday in Afghanistan, U.S. officials in Kabul said.

"We can confirm that a U.S. citizen was tragically killed in the suicide attacks in Afghanistan on December 6," the embassy said in statement released on Wednesday.

The embassy added that they have been in touch with the family of the deceased and expressed their condolences. It is the only death so far announced of a foreign citizen.  

Embassy spokeswoman Megan Ellis said the victim was not a U.S. government employee. She declined to give any further details.

A suicide attack killed 55 people at a crowded Muslim shrine in Kabul Tuesday in an unprecedented sectarian attack on a group of worshippers marking a Shiite holiday.

Also Tuesday, four people died and 21 were wounded in a smaller blast in the northern city of Mazar-i-Sharif. A bomb in a motorcycle later injured six people in the southern city of Kandahar.

Lashkar-e-Jhangvi al-Alami, a Pakistan-based militant organization, claimed responsibility for the Kabul suicide attack, NBC News reported.

"It is the first time that someone outside of Afghanistan has claimed responsibility for a attack in the country," NBC News' Mushtaq Yusufzai said.

Experts were alarmed by the sectarian nature of the attack.

"Afghanistan has been at war for 30 years and terrible things have happened, but one of the things that Afghans have been spared generally has been what appears to be this kind of very targeted sectarian attack," Kate Clark, from the Afghanistan Analysts Network, told Reuters. 

"We don't know who planted the bomb yet and it is dangerous to jump to conclusions but if it was Taliban, it marks something really serious, and dangerous, and very troubling," she added.

NBC News, Reuters and The Associated Press contributed to this report.

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