Taliban blamed for roadside bomb which killed 25 Afghan civilians on bus

A crowded bus hit a roadside bomb in southern Afghanistan yesterday, killing 25 passengers, in the latest example of Afghan civilians bearing the brunt of the country's war.

At the same time, Nato continued to investigate claims that a helicopter gunship mistakenly opened fire on a house packed with civilians, with Afghan government officials saying that 52 people were killed.

Yesterday's casualties occurred when a passenger bus was approaching Helmand province on its way to Kabul and struck the bomb. At least 20 passengers were wounded, officials said, and President Hamid Karzai condemned a "criminal" act.

The Taliban denied responsibility for the bombing but, with roadside bombs as their signature weapon, they will be blamed.

A provincial official told the BBC that the road the bus was travelling along was "mostly used by civilians and the enemies of peace should have known that a bus does not carry police or army but villagers".

A Nato spokesman also condemned the Taliban for the "tragic murder of Afghan civilians".

But the coalition has come under censure from Mr Karzai, who blamed it for a rocket attack on a crowded compound over the weekend. A statement said that Mr Karzai was "deeply saddened by the heartbreaking incident, which is both morally and humanly unacceptable" and laid the blame at Nato's door.

The incident coincided with the news that foreign forces accidentally killed many more civilians than reported between 2004 and 2009.

According to witnesses, insurgents had told a number of villagers in Helmand province to flee their homes ahead of imminent fighting, only for a Nato helicopter gunship to fire on them as they took cover several kilometres down the road.

Nato denied that version of events. It said an investigation team was on site in the village of Rigi in Sangin district, which claims to have accounted for all the rounds its forces had fired without suggestions that any had hit civilians.

Amid the conflicting reports, the UN has launched its own inquiry.