KABUL -- A provincial spokesman says four Afghan civilians have been killed and 15 wounded in a suicide car bomb attack targeting a coalition convoy in southern Afghanistan.

Spokesman Omer Zwak of southern Helmand province says the attack happened in the provincial capital city of Laskar-Gah.

Zwak had no details about how Wednesday's attack was carried out but said there were no immediate reports of casualties among coalition forces. They usually drive in heavily armored vehicles.

Insurgents have picked up the pace of their attacks after the international coalition handed over responsibility for security around the country to Afghan forces two months ago.

They have so far unsuccessfully tried to retake territory in their traditional southern and eastern heartlands.

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