AP) KABUL, Afghanistan — NATO says a suicide attack has killed three coalition troops in eastern Afghanistan, and a regional Afghan security official tells CBS News the slain troops were Americans.

The Taliban have claimed responsibility for the assault.

A coalition statement says the three troops died Wednesday morning in the province of Kunar. It provided no further details, though initial reports said the attack targeted a NATO foot patrol near the headquarters of the provincial government. NATO does not confirm the nationalities of slain troops until the families have been notified.

The account matches details given by the Afghan official to CBS News. He said at least one suicide bomber on foot approached a group of U.S. soldiers on patrol near the Kunar Provincial Council office and blew himself up.

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A spokesman for the local government, Wasifullah Wasify, told the Associated Press that at least one Afghan civilian was also killed and three were wounded in the blast.

Taliban spokesman Zabiullah Mujahid says two of the group's fighters targeted a NATO patrol in Kunar. He claims they killed several foreign troops.

So far, 212 U.S. service personnel have been killed in Afghanistan in 2012, according to the independent I-casualties organization. That figure does not include the three unconfirmed U.S. deaths reported on Wednesday. In 2011, 418 U.S. service personnel were killed in the country.