KABUL, Afghanistan - Afghan authorities say two roadside bombs have killed 14 civilians in southern Afghanistan.

Ahmad Jawed Faisal, the spokesman for Kandahar province, says a minivan ran over one bomb in Arghistan district.

Other civilians, who were riding on a tractor, arrived to help the dead and wounded, but the tractor struck a second bomb in the road.

It's not known how many people died in each blast on Sunday.

The U.N. says last year was the deadliest on record for civilians in the Afghan war, with 3,021 killed.

The number of Afghan civilians killed dropped 36 percent in the first four months of this year compared with last year, but the U.N. says that too many civilians are still being caught up in violence.