Kabul, Afghanistan ? Taliban fighters held a wedding party captive and fired on U.S. forces in an attack designed to draw U.S. airstrikes on civilians and stoke anti-American sentiment, a U.S. official said Friday citing “firsthand” reports.

The official declined to give further details of the reported events leading to the U.S. bombing Monday in the southern Afghan village Wech Baghtu, where dozens of civilians and insurgents were killed.

But such a tactic by the Taliban could mean significant complications for U.S. forces and allies – forcing them to break off attacks and pursuit of extremists in populated areas for fear that the Taliban would try to maximum civilian casualties.

Civilian deaths in Afghanistan have become an increasing point of tension between Washington and President Hamid Karzai and could be one of the first major challenges for President-elect Barack Obama.

Afghan officials said Friday a joint investigation found that 37 civilians and 26 insurgents were killed in Wech Baghtu, a village in Kandahar province, a Taliban stronghold. The U.S. official said the inquiry found that 20 civilians died. It wasn’t clear why the two sides offered differing numbers.

It is not the deadliest reported civilian death toll from a U.S. attack in Afghanistan in the last three months: An Afghan commission found that an August operation by U.S. forces killed 90 civilians in the village of Azizabad. A U.S. investigation concluded 33 civilians died.

Insurgents have always used populated areas for cover in conflicts such as Iraq and Afghanistan.

But the U.S. claim Friday represents the first detailed intelligence on an apparent Taliban strategy to bring innocent lives into the crossfire, the official told The Associated Press.

“We have firsthand knowledge that we know this was a deliberate act on the part of the Taliban to draw our forces into a fight and to cause civilian casualties, knowing that a wedding party was going on,” the official said. He spoke on condition of anonymity because he was not authorized to discuss the U.S. findings.

The official, however, did not offer additional evidence – leaving the United States open to accusations that it was trying shift blame for civilian deaths onto Taliban tactics and away from possible American battlefield mistakes.

A U.S. official last year told The Associated Press that the military believed it was possible the Taliban was deliberately trying to get U.S. forces to kill civilians, but it had no direct evidence. In past cases of civilian deaths, the U.S. has said that militants fired on its forces first from civilian areas, but no official has ever claimed the militants hoped that civilians died when the Americans returned fire.

Sarah Holewinski, the executive director of the Washington-based Campaign for Innocent Victims in Conflict, said research by her group suggests Taliban fighters often flee after firing on U.S. forces and that retaliatory bombs hit civilians.

But she said Afghan and foreign forces cannot simply ban attacks on villages, which would turn them into Taliban safe havens.

“Does this mean waiting until the Taliban flees the scene and then doing surveillance to find them, instead of bombing the village? Maybe. Bottom line is they have to figure this out. It’s the new frontier of warfare and it’s not going to end anytime soon,” Holewinski said.