An Afghan official says four people, including a district chief, have been killed by a roadside bomb in a region of northern Afghanistan that has been largely peaceful until now.

Senatullah Tumor, the spokesman for the governor of northern Takhar province, said Sunday that the bomb killed Hamidullah Haqjo Ashkamesh, chief of the Ishkashim district, as well as a police officer and two of his bodyguards.

The Taliban claimed responsibility for the attack.

The Taliban's 14-year insurgency has spread in recent months from its strongholds in the south to northern Afghanistan.

Meanwhile in southern Kandahar province, police say a roadside bomb killed a woman and wounded three people in the province's Khakrez district.