Kabul  - A suicide bomber attacked a counternarcotics police unit in southern Afghanistan Thursday, killing five officers and wounding two, a police official said.

The attack, carried out by a bomber wearing a suicide vest, took place in Lashkargah, the capital of Helmand province, when counternarcotics police were embarking on a mission, deputy provincial police chief Kamaluddin Khan said.

"The bomber jumped in front of the convoy that was leaving the station," Khan said.

Daoud Ahmadi, a spokesman for the provincial governor, said that according to their initial information, three children were also killed in the attack.

But Khan, who said he was at the scene of the attack, did not confirm the civilians deaths.

Helmand is the largest opium-producing province in the country. The Taliban are believed to be the main beneficiaries from the illicit drug business in Afghanistan. The war-torn country supplies more than 90 per cent of the world's opiates. (dpa)