British police shot one suspect and arrested another during an anti-terrorism raid in East London early Friday.

About 250 policemen, backed by the bomb squad, raided an East London house before dawn Friday in what officers describe as a major counter-terrorism operation.

Authorities say a 23-year-old man was shot during the raid and is hospitalized. He and another man, aged 20, have been arrested on charges they prepared to commit and instigate acts of terrorism. 

Neighbors say the suspects are Muslims of South Asian ancestry.

The chief of London police's anti-terrorist branch, Peter Clarke, says the raid was planned in response to specific intelligence.

"Because of the very specific nature of the intelligence, we planned an operation that was designed to mitigate any threat to the public, either from firearms or from any hazardous substances," he said.

Given the shooting, the Independent Police Complaints Commission is investigating the raid.  The IPCC commissioner, Deborah Glass, spoke with reporters after visiting the scene.

"An examination of the officers' firearms confirms that a single shot was discharged in circumstances which are currently under investigation," she said.  "We can confirm that the injuries to the man are not life threatening."

Glass declined to say if the wounded man was armed or had fired on the officers, and she says the investigation is just beginning.

"The Metropolitan Police continues to have full direction and control over the counter-terrorism operation," she added.  "I can also confirm that we have had full cooperation from the Metropolitan Police service."

The rapid involvement of the IPCC is in stark contrast to what happened last July, when London police shot and killed a Brazilian man they mistook for a terrorist. It was several days before the IPCC began to look into that shooting, which had followed suicide bomb attacks on London's transportation system that had killed 52 passengers.