KABUL, Afghanistan - Afghan elders claimed Saturday 108 civilians were killed in a bombing campaign in western Afghanistan, while villagers in the northeast said 25 Afghans died in air strikes, including some killed while burying dead relatives at a cemetery.

U.S. and NATO leaders, though, said they had no information to substantiate such claims, and a U.S. military officer said Taliban fighters are ordering villagers to say civilians died in fighting -- whether they did or not.

Even Afghan officials who reported the deaths Saturday said they couldn't confirm the claims, which came from dangerous and remote regions that journalists and other independent researchers couldn't reach because of ongoing fighting or road closures.

The claims and denials of civilian deaths are part of an increasing campaign of information warfare that the Taliban and Western militaries are engaged in alongside conventional fighting on the ground.

But it leaves the basic question unanswered: Are the latest claims true? No one can yet say.

"It is a very problematic information environment,'' said Adrian Edwards, the UN spokesman in Afghanistan.

Edwards said the UN hasn't been able to confirm any of the most recent casualty claims. "If figures are coming up quickly, it's my sense that they probably need to be taken with a pinch of salt,'' he said. "But it also doesn't help if it's two or three weeks before the information comes out.''

In western Farah province, Abdul Qadir Daqeq, chief of the provincial council, said elders from the Bala Baluk district delivered a letter to his office saying 108 civilians _ including women and children _ had been killed in air strikes Thursday and Friday. Thirty-three militants were also reported killed. Eleven police were also found beheaded on the battlefield.

"The area is under the control of the enemy,'' Daqeq said. "No one can go to Bala Baluk to find out the exact number of casualties. I cannot go there, human rights officers can't go there, government officials can't go there.''

Maj. John Thomas, a NATO spokesman, said air strikes were called in to assist Afghan forces in Farah, but officials have "no information'' to support the civilian casualty claims. He said there was a "significant effort'' to move civilians out of the area before the fighting started.

In northeastern Kunar province, Gov. Shelzai Dedar said villagers told him 25 civilians had been killed during fighting, which also left two NATO and two Afghan soldiers dead over the past several days. Dedar said 20 militants were killed, while the Ministry of Defence said 37 died.

Other government officials said some civilians in Wata Pur district were killed by an air strike while burying dead relatives. "It's too dangerous to go there, but we heard these rumours from the people,'' Dedar said.

Thomas said NATO was "as confident as we can be at this point that we struck only at firing positions in a remote area, and the only individuals who died were insurgents.''

He said officials were "keenly interested'' in finding out any information that would substantiate the claims of civilian deaths.

Civilian casualties are a recurring problem that Afghan President Hamid Karzai has repeatedly deplored.

Independent counts of civilian deaths by the UN and The Associated Press both show U.S. and NATO forces have caused more civilian casualties this year than Taliban militants have.

About 600 civilians have been killed so far this year by both sides.

Lt.-Col. Rob Pollack, a U.S. officer at the main American base in Bagram, said Taliban militants have been told to fight in civilian areas because civilian deaths caused by U.S. or NATO forces provide a propaganda victory.

"In the south, villagers are being told by the Taliban that if they do not call in and report civilian casualties, they will be punished,'' said Pollack, who said payments to the families of Afghans killed or wounded in fighting could also be fuelling the claims.

Pollack said in a recent battle Taliban militants pulled civilians into a trench they were fighting from, leading to some Afghan deaths. The UN's Edwards said the Taliban have "repeatedly used civilians to achieve their aims.''

Qari Yousef Ahmadi, who claims to speak for the militants, said there was "no need'' to use civilian homes during fighting. He denied that militants are forcing villagers to increase claims of casualties.

More than 3,100 people, mostly militants, have died in insurgency-related violence this year, according to an AP count based on Western and Afghan officials.