Five civilians were killed and three others wounded when the taxi in which they were riding struck a roadside bomb in southern Afghanistan.

The explosion came late Saturday in the Panjwaii district of Kandahar province, where NATO troops and Taliban fighters have engaged in a number of several battles over the last 18 months.

Panjwaii district chief Shah Baran said such improvised explosive devices (IEDs) are often aimed at Afghan and NATO forces, "but this time it exploded on civilians."

Canada has about 2,500 troops operating in Kandahar province, one of the most violent regions in the country. Seventy-seven of them have died since 2002, along with a Canadian diplomat.

Most of the deaths have been the result of IED attacks.

Trooper Richard Renaud was killed on Tuesday, when a roadside bomb blew up his light-armoured vehicle while he was on reconnaissance north of Kandahar.

As many as 1,977 civilians were killed in insurgency-related violence in 2007, according to a year-end report by the Afghanistan NGO Safety Office.

The report said that suicide attacks, IEDs, gunfire, hangings and mortar fire killed 933 Afghan civilians. It also reported that international forces killed 525 civilians in ground manoeuvres and with aerial bombing.

With files from The Associated Press