A suicide bomber killed 13 people and wounded at least 20, in an attack on a minibus carrying police cadets in the main city in Afghanistan's turbulent east on Wednesday, a government spokesman said.
Ahmadzia Abdulzai, a spokesman for the governor of Nangarhar province, said the bomber had rammed an explosives-packed car into the bus carrying cadets in Jalalabad city.
"It was a suicide attack against a small bus carrying Afghan police," Abdulzai told Reuters.
Nearby cars and trucks lay upturned by the blast while pieces of human flesh were scattered across the street amid the debris, even as members of the Afghan National Police and local residents carried away scorched bodies.
"The dead and wounded include police and civilians," Abdulzai added.
Afghan and foreign security forces, as well as government officials, are often targeted in attacks by insurgents.
The Taliban said at the beginning of this month that it had begun its long awaited "spring offensive" and senior US commanders said they expected a significant spike in violence.
US and NATO commanders have claimed major success against insurgents in the south over the past 12 months, but insurgents in the east have proved harder to pin down.
While the Taliban dominates the insurgency in the south, the fight in the east is more fragmented and includes other groups such as the al Qaeda linked Haqqani network.
Despite the presence of around 150,000 foreign troops, violence across Afghanistan last year reached its worst levels since the Taliban was overthrown in late 2001, with record casualties on all sides of the conflict.