For more than a week, residents watched with growing edginess as police and helicopters stepped up patrols around Dalgarno Gardens (search) — a quiet street on the edge of London's trendy Notting Hill area.

On Friday, police descended en masse, swooping in with guns and stun grenades, posting marksmen on rooftops and finally forcing suspects to emerge in their underwear, hands above their heads.

In the dramatic raids, police targeted one apartment complex on Dalgarno Gardens and another about a mile away in Tavistock Crescent (search), making three arrests in all.

Dalgarno Gardens — a center of the terrorist hunt — is a mixed-income, multiethnic street whose residents include bus drivers, shopkeepers and their families. Tidy Victorian-era brick cottages stand beside more modern apartment buildings.

Residents said they'd felt growing pressure since the deadly transit bombings July 7, the botched attacks July 21, and last week's discovery of an unexploded bomb near Little Wormwood Scrubs park, just down the road.

The raid on the Peabody Estates apartment complex began about 11 a.m. when neighbors heard a loud explosion and cracks that sounded like shots. Officers with guns and gas masks flooded into the sprawling project of low-rise brick buildings. Police marksmen were seen on rooftops, and a helicopter flew overhead.

"I was in the bedroom minding the baby when I heard a massive explosion," said one neighbor, Palmira Morais. "I looked outside to see what was going on, and I saw loads of police and the building was cordoned off. We went outside to see what was happening and the police asked us to move."

Other neighbors heard police yelling at a man in an apartment to come out in his underwear with his hands up. "He was yelling, 'No way! You're going to shoot me,"' said Alex Ospina.

Another witness, Nicolas Holliman, said he saw four officers with guns and rifles, and a specialist firearms officer, all focused on a top floor apartment and calling for someone they referred to as "Mohammed."

"He was being asked to come out with his hands up, naked or in underclothes," Holliman said. "They were ... telling him he would be safe if he puts his hands up."

Holliman heard what he believed was gas being fired at the flat, and then silence.

Later, television footage showed two bare-chested men, hands above their heads, standing on an apartment balcony. Two policemen in blue overalls led away a man in white overalls, said neighbor Philomena Daly.

Osama Ahmed Ali, 16, said he recognized one of the men being taken away — his wrists in plastic cuffs — as his Somali neighbor, a bus driver. "His face did not have any reaction on it," Ali said.

Another bus driver, 40-year-old Dave Jones, said he lived next to the raided apartment, where he thought six Somali men lived.

One of those arrested was believed to be Muktar Said Ibrahim (search), 27, who allegedly tried to blow himself up on a double-decker bus in east London. Ibrahim, also known as Muktar Mohammed Said, came to Britain in 1990 from Eritrea.

The suspect arrested with him identified himself as Ramzi Mohammed, said Peter Clarke, head of the Metropolitan Police's anti-terrorist branch. A police official said Mohammed was the suspect shown wearing a "New York" sweatshirt and believed responsible for the attempted bombing near Oval Tube station.

A third man arrested in Tavistock Crescent was not immediately identified.

In Rome, police announced they had arrested Osman Hussain, a naturalized British citizen from Somalia.

On Dalgarno Gardens street, some neighbors, like Ospina, called the raid "shocking."

But others seemed less surprised, citing the intense police presence of the last week. "There's been an air of expectancy," said another neighbor, 36-year-old Stefane Morris. "We all got the impression someone was somewhere near here."