US forces 'kill Afghan police'

Two hours into the battle, US forces arrived and mistakenly opened fire on the police, said Khogyani district police chief Zurmai Khan.

A police spokesman said a US helicopter fired rockets, killing seven policemen and wounding four.

"I think there was a misunderstanding - the helicopter opened fire at the police post," he said.

Police manning a remote checkpoint in Nangarhar province said an American convoy backed by helicopters approached and opened fire despite their protests and calls for them to stop.

"I thought they were Taliban, and we shouted at them to stop, but they came closer and they opened fire," said Khan Mohammad, one of the policemen at the post, adding: "I'm very angry. We are here to protect the Afghan government and help serve the Afghan government, but the Americans have come to kill us."

A spokeswoman for Nato's International Security Assistance Force said she had no information that US forces that fall under ISAF's command were involved. A spokesman for the separate US-led coalition said he was looking into the report.

Meanwhile, a US-led coalition and Afghan troops killed more than 24 suspected Taliban fighters during an eight-hour battle in in Shah Wali Kot in Kandahar.

Elsewhere Nato says its soldiers killed three civilians in Kunar province.

The International Committee for the Red Cross says the security situation in Afghanistan is deteriorating.

In a report marking 20 years of its work in Afghanistan, the ICRC said life for ordinary people in Afghanistan was getting worse.

"It's really had a heavy price in terms of the population, both in terms of wounded and in terms of killed and people displaced so it's a very worrying situation," the ICRC's director of operations, Pierre Kraehenbuhl, said.