NADAHAN VILLAGE, Afghanistan – NATO and the Afghan government on Thursday blamed the Taliban for a wedding party bombing that killed at least 40 people.

But the Taliban claimed they played no role in the blast in the Arghandab district, an insurgent stronghold near the southern city of Kandahar.

Stunned survivors said they suspected a NATO airstrike was responsible, a view that reflects either their deep suspicion of the U.S.-led coalition or fear of Taliban retribution.

Regardless of responsibility, Wednesday night’s attack is likely to heighten public concern about a planned NATO military operation in the Kandahar area, the birthplace of the Taliban considered by U.S. commanders as the key to turning back the insurgents.

The top U.S. and NATO commander, Gen. Stanley McChrystal, acknowledged Thursday that the Kandahar operation will take longer than planned because local Afghans do not yet support it.

Interior Ministry spokesman Zemeri Bashary said the attack occurred when a suicide bomber entered a rural home where men were celebrating a wedding. The groom was among the 74 wounded. Women guests were in a separate house with the bride.

Nevertheless, suspicion fell on the insurgents because the family included a number of Afghan policemen, who are often targeted by the Taliban.

Kandahar provincial Gov. Tooryalai Wesa said doctors at the city hospital had recovered ball bearings from the bodies of the dead. Militants often pack ball bearings and other metal into suicide vests to kill more victims.

“The Taliban are doing two things at once,” Wesa told reporters. “On one side they target people who are in favor of the government. Then at the same time, they don’t want people to know their real face.”

In this sun-baked farming village of mud-walled compounds, survivors said they were skeptical that the blast was caused by a suicide bomber because the damage was so extensive. “If it were a suicide attack, there would be some hole in the ground,” said Abdul Raziq, a member of the village defense militia.

Mohammad Rassool, a cousin of the groom, said he saw helicopters, including one with guns in the front, flying above the compound before the explosion.

“I was coming toward the wedding and on the way I saw something from a helicopter move toward the village,” Rassool said. “After we saw the smoke and fire come up, we knew that a rocket had hit. Why would the Taliban do this when we are not against each other?”

U.S. military spokesman Col. Wayne Shanks denied any coalition airstrike in the area at the time of the attack. Civilian deaths are a sensitive issue in Afghanistan, and the NATO command has apologized for attacks that kill civilians.

Nevertheless, public support for the U.S.-led mission is weakest in the dusty farming communities of southern Afghanistan.