KANDAHAR, Afghanistan—Residents of an Afghan village near where an American soldier is alleged to have killed 16 civilians are convinced that the slayings were in retaliation for a roadside bomb attack on U.S. forces in the same area a few days earlier.

In accounts to The Associated Press and to Afghan government officials, the residents allege that U.S. troops lined up men from the village of Mokhoyan against a wall after the bombing on either March 7 or 8, and told them they would pay a price for the attack.

The lawyer for Army Staff Sgt. Robert Bales, who is accused in the March 11 killings of the 16 civilians, has said that his client was upset because a buddy had lost a leg in an explosion on March 9.

It’s unclear if the bombing cited by attorney John Henry Browne was the same as the one described by the villagers that prompted the alleged threats. After a meeting at a military prison in Fort Leavenworth, Kansas, Browne said Bales told him a roadside bomb blew off the leg of one of his friends two days before the shootings occurred.

A spokesman for the U.S. military declined to give any information on the bombing or even confirm that it occurred, citing the investigation of the shootings. He also declined to comment on the allegation that U.S. troops threatened retaliation.

“The shooting incident as well as any possibilities that led up to it or might be associated with it will be investigated,” Lt. Col. Jimmie Cummings, a spokesman for U.S. forces in Afghanistan, said Tuesday.

Bales, 38, is suspected of leaving a U.S. base in Panjwai district of Kandahar province, entering homes and gunning down nine children, four men and three women before dawn on March 11 in the villages of Balandi and Alkozai. Mokhoyan is about 500 yards (meters) east of the base.

The shootings have further strained ties between the U.S. government and President Hamid Karzai who has accused the U.S. military of not cooperating with a delegation he appointed to investigate the killings.

Karzai’s investigative team is not convinced that one soldier could have single-handedly left his base, walked to the two villages, and carried out the killings and set fire to some of the victims’ bodies.

The identity of the soldier who allegedly threatened the villagers is not known.

• Deb Reichmann, Associated Press