A roadside bomb killed four US soldiers in south Afghanistan on Tuesday, officials said, the latest fatalities for the NATO-led coalition which is winding down after 12 years of fighting.
The soldiers died in the volatile province of Kandahar, where five US troops were killed by a similar improvised explosive device targeting a vehicle on May 4.
Kandahar is a hotbed of insurgent activity, with large areas under the control of Taliban militants who were ousted from power in Kabul in 2001 after the 9/11 attacks on the United States.
"We can confirm that four soldiers were killed in a roadside bomb in southern Afghanistan today," a spokesman for the NATO International Security Assistance Force mission said, following policy by not specifying their nationality.
Javid Faisal, spokesman for the provincial government of Kandahar, told AFP that the victims were American.
"At around 2:30 pm, a NATO armoured vehicle hit a roadside mine in Zhari district. We have learned that four US soldiers inside the vehicle have been killed," he said.
This year, 46 US soldiers and 13 troops from other coalition nations have died in Afghanistan, according to the independent "icasualties" website.
Three Georgian soldiers were killed in neighbouring Helmand province on Monday when a suicide bomber detonated a vehicle laden with explosives.