KABUL: A security official says a suicide car bombing has killed four people, two civilians and two policemen, in southern Afghanistan.

Police spokesman for southern Helmand province, Shamem Noorzai, says Wednesday's attack took place in the Gareshk district.

He says the bomber targeted a police patrol and blew up his car next to a police vehicle in a crowded area of the town of Gareshk.

Noorzai says the explosion also wounded three civilians and a police officer.

Helmand's provincial spokesman, Omer Zwak, says another attack, this one in Gramsir district, killed two people when the fuel truck they were driving in struck a roadside bomb.

Afghan insurgents are planting an increasing number of bombs across the country in a campaign to retake territory as foreign forces withdraw from Afghanistan.