LONDON - Armed police raided a West London apartment on Friday in their hunt for would-be suicide bombers and cornered a suspect who refused to come out.
"Take your clothes off. Exit the building," police were heard shouting.
A witness, identified as Lisa Davis, told Sky News television by phone: "Five armed police with guns and shields are moving in. They are telling everyone to get inside now.
"They are asking him, 'What is the problem? Why can't he come down?"
Police are still chasing three of four men who tried to detonate bombs in failed attacks on July 21, exactly two weeks after a team of four suspected Islamist militant bombers killed themselves and 52 other people in London.
On Davis's phone, viewers could hear police shouting for the suspect to leave. Calling the man Mohammed, they told him if he did so, he would be safe.
Sky TV, citing police sources, said the operation targeted at least one of three suspected bombers still at large. The fourth was arrested on Wednesday.
A Sky reporter said he understood one person had been arrested in Friday's operation.
A spokesman at Scotland Yard police headquarters said: "We are in the early stages of an armed operation."
"It's in connection with the attempted bombings on July 21 and cordons are in place as a precaution," he added.
Blast Heard
Local resident Martin Pendergast told Reuters by telephone: "Police have sectioned off my estate and the (nearby) Sutton estate."
He said he had heard some sort of blast. "It sounded like a kind of version of a firework mixed with a shotgun," he added.
Another witness reported up to six explosions and said he had been told by police they were caused by stun grenades.
Police specialists in forensic suits and gas masks were seen preparing to enter a housing estate in the Ladbroke Grove area.
Two days after the four failed bomb attacks, police said they had found in what appeared to be a fifth device abandoned in bushes in the Wormwood Scrubs area of west London.
Wormwood Scrubs is only a few hundred yards from the scene of Friday's raid.
Police have been under pressure to exercise caution after they shot dead Brazilian Jean Charles de Menezes in London last Friday because they mistook him for a suicide bomber.
In the biggest manhunt ever undertaken by British police, London police chief Ian Blair said he was confident the three would-be bombers on the run would be caught.
"How soon it will be, I don't know. But I am quite sure the net is closing," he said on Thursday evening.
Police are reviewing 15,000 closed circuit television tapes, have taken 1,800 witness statements and received 5,000 calls on their anti-terrorism hotline.
Feeds