Officials in southeastern Afghanistan say unknown gunmen have shot dead the local Red Crescent Society director.

The Red Crescent director for Zabul province was killed Saturday while travelling to his home village from the provincial capital of Kalat.

His brother, who was also in the vehicle at the time of the attack, survived unharmed.

Officials are uncertain whether the incident is the work of militants waging an anti-government insurgency in the region.

Zabul was the site of a string of terrorist incidents last year linked to the insurgency, led by remnants of Afghanistan's former hardline Taleban regime.

After months of relative clam, the province saw a new outbreak of violence Friday when assailants shot and killed a Turkish engineer working on a local reconstruction project, along with his guard.

Authorities blamed Friday's attack on Taleban militants.

Lieutenant Colonel Bryan Hilferty, spokesman for U.S. forces in Afghanistan, says the militants' choice of aid workers and other civilian targets is a sign of their increased weakness.

"We think it's an example of the terrorists' desperation when they continue to attack the people who come to Afghanistan," he said.

Afghan and U.S. troops continue to engage militants in battle, with nine suspected insurgents killed in the southeastern Afghan province Paktika during a clash on Friday.