KABUL - Seven Afghan security guards were killed today when their car hit a roadside bomb in eastern Afghanistan.

Police say the guards, who worked for a road construction company, hit the bomb in Kunar province, in a mountainous region close to the border with Pakistan.

In another incident in Kumar, Police say a gunman shot and killed the police chief of Chawkey district Friday night.

One man was arrested in connection with the case.

Last year was Afghanistan's most violent since the 2001 ouster of the Taliban.

More than 6,500 people died in insurgency-related violence, according to an Associated Press count based on official figures.