WOOTTON BASSETT, England — Thousands of mourners bowed their heads in tribute Friday to the passing coffins of British soldiers killed in a new offensive in Afghanistan, where the climbing toll has created doubts in Britain about the human cost of the war.

News of 15 battlefield deaths in 10 days has many Britons rethinking the country's commitment to a conflict that seems no closer to a successful conclusion than when troops first arrived seven years ago.

A Ministry of Defense spokeswoman said a total of eight deaths were announced Friday, making it one of the darkest days of the war. She spoke on condition of anonymity, in line with department policy.

"The casualties should fix peoples' minds on the fact that we've let the soldiers down," said Adam Holloway, an opposition Conservative Party lawmaker who sits on Parliament's defense committee. "The death toll means we should do it properly or we shouldn't do it at all."

Holloway, a frequent visitor to Afghanistan, said Britain has never had the troop strength needed to hold ground there and has failed to provide the promised security or reconstruction, leading many Afghans to believe the Taliban militants will outlast Western forces.

"We're in a mess," he said.

He cautioned that there is still no widespread public revolt against the government's war policy. He said his constituents do not seem extremely worried about the troubled Afghan campaign, despite the increasing casualties.

But some communities are grieving. Schoolchildren, businessmen and army veterans stood side by side in Wootton Bassett, a small market town about 85 miles west of London, as the bodies of five soldiers killed between Saturday and Tuesday were driven through the crowds after being flown to a nearby air base.

Wootton Bassett's mayor, Steve Bucknell, said it was becoming increasingly hard to accept the rising number of British casualties.

"We keep on asking ourselves, How many more? Each time we pray it's the last one, knowing it probably isn't going to be," Bucknell said.

It has become traditional for the residents to line the streets when hearses carrying soldiers' coffins pass through the town on the sad trip from a military airport to a cemetery.

The casualty count mounted Friday night when officials said five soldiers had been killed in two separate explosions while on patrol. Earlier in the evening, the Ministry of Defense announced that a soldier from the 2nd Royal Tank Regiment had been killed in an explosion. Two other deaths were announced earlier in the day.

The names of the dead soldiers are likely to be released in the next 24 hours.