Ten Afghan security guards have been killed in the latest attack by insurgents in the south of the country.
They were escorting a convoy carrying supplies for Nato troops.
The head of the security company said 80 of his guards had fought a battle with a large group of Taleban fighters in the southern province of Zabul.
Earlier on Thursday, three civilians were killed in a bomb attack on a police convoy in Helmand province, as they walked along the roadside.
The provincial police chief, who was in the convoy, was not injured.
Local officials have blamed the attack on the Taleban, who are waging an increasingly bloody insurgency in southern Afghanistan.
Officials also said that on Wednesday night, two Canadian soldiers and their Afghan translator were killed by a roadside bomb in the southern province of Kandahar.
Two journalists travelling with them were also injured in the overnight attack.