HERAT, Afghanistan, April 1, 2008 (AFP) - A suicide attacker blew up a car bomb inside a district police compound in southwestern Afghanistan Tuesday, killing two policemen and wounding five, police said.

Police had brought the bomb-filled car into the compound in Khash Rod district of Nimroz province after it had had an accident with a police vehicle, provincial deputy police chief Assadullah Sherzad told AFP.

'Policemen involved in the accident brought the civilian vehicle and driver to the police headquarters for the usual paper work. As they entered, the driver detonated his car bomb,' he said.

'It killed two policemen and wounded another five. It was a suicide car bomb,' he said. Five police vehicles were damaged.

It was not clear if the bomber had intentionally collided with police.

There was no immediate claim of responsibility for the attack, similar to scores carried out by militants allied with the insurgent Taliban movement.

The provincial governor, Ghulam Dastageer Azad, told AFP the policemen who had been in the car accident were involved in campaigns to destroy fields of illegal opium poppies in the province, which borders Iran.

Taliban rebels attacked a counter-narcotics police force in the same district on Friday, triggering a fierce clash that left two officers and 10 militants dead.

The United Nations has said that Khash Rod is an important poppy-growing area with a strong increase in opium production expected in the province this year.

Afghanistan is the world's top producer of illegal opium, which is used to make heroin, accounting for more than 90 percent of the global supply.