KABUL, Afghanistan - Twelve Afghan civilians died in roadside bomb blasts in the past 24 hours, officials said Wednesday.

Homemade bombs planted on roads or near government buildings have become a major killer in Afghanistan as the Taliban and other militants increasingly use guerrilla tactics to battle Afghan and international forces. The bombs usually target the military, but civilians are also frequent victims.

On Wednesday morning in southern Kandahar province, a family of seven died when their vehicle struck a bomb in Panjwai district, said Zalmai Ayubi, a spokesman for the governor. All in the car were killed including two young children, he said.

Another bomb blast on Tuesday afternoon killed five people in western Farah province, according to Raouf Ahmadi, a police spokesman for the western region.

They were traveling in a private van toward neighboring Ghor province when their vehicle hit the bomb, he said. Eight others in the van were wounded.

A UN report said 1,013 civilians were killed in the first half of 2009, a 24 percent increase from the same period last year. More than half of those killed -- about 60 per cent -- died in militant attacks. Airstrikes by international forces were also a major killer.