KABUL, Afghanistan — New details that emerged today show that eight U.S. troops who were killed while on foot patrol in southern Afghanistan the day before were hit by two consecutive blasts, with one explosion going off as troops rushed to aid those wounded from the first blast, NATO said.

The Taliban has claimed responsibility for Thursday’s attack in the southern Kandahar province.

It was the deadliest day for NATO in Afghanistan since April 27, when a veteran Afghan military pilot killed eight U.S. troops and an American civilian contractor at Kabul airport.

The Kandahar attack started as the troops began to inspect a suspicious object they found while patrolling on foot in the mountainous Shorabak district. The first explosion wounded some of the service members, while the second came as others tried to help the injured, NATO said. U.S. officials have confirmed that all eight victims were Americans. Two Afghan policemen also died and two others were wounded.

Separately, NATO today announced the death of a service member killed in an insurgent attack, also in southern Afghanistan. Forty international service members have been killed so far this month, while so far this year, 191 coalition troops have died in Afghanistan.

Insurgents declared the start of a spring offensive on May 1 against NATO and the Afghan government.