TAKHAR, Afghanistan - A suicide bomber targeted a joint convoy of Afghan and NATO-led forces on Thursday in northern Afghanistan, killing at least six police, an official said.
Largely active in the south and east, the Taliban have stepped up their attacks in recent months in some areas of the north, which was regarded relatively safe.
"The bomber was in a car and struck the convoy. Six police and one pro-government guard were killed," Abdul Rahman, a senior provincial police officer told Reuters.
Violence in Afghanistan is at its worst since US-led and Afghan armed groups overthrew the Taliban from power in 2001. June was the bloodiest month for foreign forces in the 9-year-war with more than 100 killed.
Hundreds of Afghan civilians have also been killed this year as they become increasingly caught up in the crossfire.
Despite a record number of foreign forces in Afghanistan, standing at some 140,000, backed by tens of thousands of Afghan forces, the Taliban have managed to spread their campaign out of their traditional powerbases and into the north of the country.
Kunduz has taken the brunt of the Taliban attacks in the north and insurgents are increasingly using it as a base to launch attacks elsewhere in the region.
To try and counter this, the United States has been sending hundreds of troops to the north, which had previously been under sole control of some 4,000 German troops who are bound by severe combat restrictions introduced after the second World War.