KANDAHAR, Afghanistan: A bomb killed 13 civilians including women and children in southern Afghanistan on Monday as they travelled to attend the funeral of earlier bomb victims, police said.

It was the latest violence since the Taliban launched their annual “spring offensive” on April 27, opening a crucial period for the country as its security forces take the lead in offensives against the insurgents.

“The blast hit a pick-up truck in the Arghistan district of Kandahar province, killing four women, four men and five children,” Abdul Raziq, Kandahar provincial police chief, told AFP.

Raziq said the victims were travelling to the funeral of two people who were killed by a similar blast a few days ago.

“A motorbike earlier hit a roadside bomb that killed two people, and today's victims were travelling to attend that funeral when unfortunately their vehicle struck another bomb,” he said.

Javed Faisal, Kandahar provincial governor spokesman, confirmed the incident.

“All the victims are civilians,” he said. “The bomb was planted by Taliban insurgents in a district that borders Pakistan and civilians are often the victim of these bombs.” Nine people were injured in the blast, some of them suffering life-threatening wounds, officials said.

The Taliban, who are fighting to oust the US-backed government of President Hamid Karzai, deny deliberately targeting civilians.

No large-scale attacks have been launched since the offensive was announced. But five US soldiers died in a Taliban bomb blast also in Kandahar and another bomb killed eight Afghan police in Logar province.

All Nato combat missions will finish by the end of next year and the 100,000 foreign troops deployed across Afghanistan have already begun to withdraw from the battlefield.

More than a decade after the Taliban government was toppled in 2001, Afghanistan remains in the grip of a violent insurgency, with militants launching daily strikes on government officials, police and international and Afghan soldiers.

As Afghanistan's inexperienced security forces take over responsibility for fighting the Taliban, fears are growing that the country could tip into civil war after Nato military operations cease.

The “residual” US force, ranging from about 2,500 to 12,000 troops, is likely to stay in Afghanistan to focus on Al-Qaeda militants and further training of the national police and army.

Also on Monday, Taliban leaders pledged to release the final four Turkish engineers held hostage since their helicopter crashed in eastern Afghanistan last month.

Four other Turkish engineers aboard the helicopter were freed on Sunday.