The mayor of Kandahar survived an attack on his convoy on Sunday
A roadside bomb attack in eastern Afghanistan has killed four US soldiers, the Nato-led Isaf peacekeeping force has confirmed.
Taleban insurgents reportedly claimed responsibility for the explosion which killed the servicemen in the province of Nangarhar.
Reports suggest that the bomb went off as a convoy was passing.
More than 60 foreign soldiers have been killed in the country this year, many of the losses claimed by the Taleban.
The BBC's Martin Patience in Kabul says that in the face of the worsening security situation, the US is set to deploy thousands of additional troops in an effort to bring greater stability.
Supply base hit
A separate attack on a Nato patrol in Kabul killed two bystanders on Sunday.
Attackers also hit a Nato supply terminal in Pakistan
The suicide bombing injured 14 civilians; no foreign troops were wounded or killed.
The mayor of the city of Kandahar also survived a bomb attack, which happened on his convoy; one bystander died and six others were injured.
Elsewhere, in Kandahar's Maywand district, the US military says five militants were killed in an operation involving US and Afghan troops.
Meanwhile, militants in Pakistan attacked a transport terminal used to supply Nato forces in Afghanistan, destroying about 20 lorries.
Police say the attackers used rockets and petrol bombs in the assault on the depot in the city of Peshawar.
Afghan suicide blast near Kabul
The incidents follow the deaths of three other soldiers from the International Security Assistance Force (Isaf) in Afghanistan on Saturday.
A French soldier and five Afghan troops died during a clash with militants in Kapisa province; a British soldier was killed in an explosion in southern Afghanistan; while the third Isaf soldier, whose nationality was not released, died in a traffic accident in the north of the country.
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