KABUL, Afghanistan — Five American soldiers were killed in a helicopter crash in southern Afghanistan on Monday, officials said Tuesday.

Officials said that the crash, which happened around 11 p.m., was under investigation, but that “there was no enemy activity in the area at the time.” The coalition said that the wreckage of the Black Hawk helicopter had been removed from the site, in the Daman district of Kandahar Province, and that it would be analyzed for evidence of what brought it down.

The crash brought the American death toll on Monday to seven, making it the deadliest day this year for United States forces. Earlier, two soldiers were killed in an insider attack in eastern Afghanistan. In that attack, an Afghan police officer opened fire with a gun mounted on the back of a truck, killing two members of the American Special Operations forces, wounding 10 others and killing several members of the Afghan security forces. It was the second insider attack in three days.

Also on Monday, American soldiers fired on a civilian vehicle on the outskirts of Kabul, killing two people. Coalition officials said the driver had failed to heed warnings to steer away from a United States military convoy. The shooting was under investigation, said Col. Tom Collins, a spokesman for the International Security Assistance Force.