Five officers killed as bombers target police

The blast, which also wounded 19, went off in a car park outside the police building in Kandahar, said Saisal Ahmad, a spokesman for the provincial government.

The blast was large enough that it shattered windows in nearby buildings. No one immediately claimed responsibility.

In the north, meanwhile, Afghan police said that an American soldier shot and killed an Afghan guard at a US base, apparently because the American thought the guard was about to attack him.

There has been a growing number of attacks by Afghan soldiers against international forces in Afghanistan in recent years, some the result of arguments and others by insurgent infiltrators.

Last month, an Afghan soldier shot and killed four unarmed French troops at a base in eastern Afghanistan.

Friday’s shooting in Sari Pul province in northern Afghanistan resulted from an unfortunate misunderstanding, said Sayed Jahangir, the deputy police chief for the province.

US forces were “aware of an incident in northern Afghanistan” and were investigating, said US military spokesman Lt Col Jimmie Cummings.

He declined to provide further details.