Seven United States soldiers have been killed and one is missing after an explosion at a weapons cache where they were working in Afghanistan.
Three others were injured in the blast in the southern province of Ghazni on Thursday, and they have been taken to Bagram air base near the capital Kabul.
It is not yet clear what caused the latest explosion.
Three people - including peacekeepers from Canada and the UK - have been killed in suicide bombings this week.
A US spokesman said an interpreter was also injured in Thursday's incident.
He said: "The soldiers were working around a weapons cache when the explosion occurred.
"The wounded soldiers were evacuated to the 452nd Combat Support Hospital at Bagram Air Base."
Major US presence
The BBC's Andrew North, in Kabul, said initial reports suggest that the soldiers were trying to move weapons from the cache when they detonated.
The US military leads a 12,000-strong force in Afghanistan hunting Taleban and al-Qaeda members still in the country since the US-led campaign removed the Taleban from power in 2001.
In the last few days, Kabul has been the focus of suicide bomb attacks said to have been carried out by the ousted Taleban.
A British soldier was killed in the Afghan capital on Wednesday when a car laden with explosives hit his vehicle.
On Tuesday a suicide bombing in the city killed a Canadian member of the international peacekeeping force.