Officials say a roadside bombing in southern Afghanistan has killed a district police chief, as the insurgents increasingly target Afghan security forces amid the drawdown of foreign troops.

Ahmadulah Nazik, who is the administrator of Dand district in Kandahar province, said Rahmatullah Khan died Saturday while trying to reach a police outpost under Taliban attack.

The killing comes a day after four policemen were shot dead in southern Helmand province by their own colleagues. Taliban spokesman Qari Jusuf Ahmedi said the killers fled and joined the guerrillas.

The U.S.-led NATO coalition is continuing its drawdown toward a planned withdrawal of the majority of combat troops in 2014. Insider and other attacks have thrown doubt on the capabilities of the Afghans to maintain control after the transition.