An Afghan official says that at least six civilians died when their rickshaw struck a roadside bomb in the country's southwest.

Ahmad Arab, the spokesman for the provincial governor in Nimroz province said on Thursday that the explosion happened the night before. The six killed included four children, a woman and a man who were all relatives.

Arab says another civilian was wounded in the bombing in Khashrod district. No group has so far claimed responsibility for the attack.

The bombing came a day after the Taliban announced their spring offensive in Afghanistan. A statement to media said it would begin on Friday.

This fighting season will be the first time the insurgents' annual campaign against the Afghan government will take place without NATO troops on the battlefield.