KABUL - Eight civilians in one family, including six children, were killed in a NATO air strike after a field operation in Paktia province, local government officials told NBC News.

The incident took place at 8pm on Saturday in the Garda Serrai district, according the Paktia government spokesman Rohullah Samoon.

They were all members of one family, he said.

NATO said told NBC News it was taking the reports of the incident seriously and was investigating.

Samoon told Reuters said the air strike was not coordinated with Afghan security forces on the ground in the area.

Civilian casualties have been a major source of friction between President Hamid Karzai's government and U.S.-led NATO forces in Afghanistan, Reuters reported.

NATO is preparing to hand over all security responsibilities to Afghan forces and most foreign combat troops are scheduled to leave the country by the end of 2014.

Khyber Shinwari, NBC News, contributed to this report.

More world news from msnbc.com and NBC News:

• UN: 32 children, dozens of adults killed in Syrian town
• Budget cut overkill? Canada axes entire marine pollution program
• Weakened Fukushima nuclear pool is not unstable, Japan insists
• Scotland launches independence campaign with 007's support
• Runoff could take Egypt's voters on one of two very different paths
• Leftist tipped to be next Greek leader warns of 'Cold War' over austerity

Follow us on Twitter: @msnbc_world