LONDON — One of the men who lived at a house that was raided by police in London was a mixed-heritage former student who had become interested in Islam after leaving university, his next-door neighbor said yesterday.

He lived with his parents, an architect and an accountant, in a modern terrace house in Walthamstow, east London, which was stormed by officers at 1 a.m. yesterday.

A 66-year-old retired fireman, his neighbor, Paul Kleinman, said that, as a boy, he enjoyed a game of soccer and playing the trumpet before he went to university about seven years ago.

But when he dropped out of school, he began to wear traditional Islamic dress and grew a beard.

A father of three, Mr. Kleinman said the man’s father was Middle Eastern and that his mother was of European descent. He said he had an older brother who had already left home and now worked in computers.

He said: “We have always got on very well with the family. When the second son was born, a lot of neighbors went around for a drink. We used to send them all Christmas cards.

“Both boys went to university, but the youngest dropped out. He suddenly grew a beard and started wearing Muslim robes. He had a lot of friends who dressed similarly who came around all the time. But his parents never said they were worried about him.”

Mr. Kleinman said the house was raided in the early yesterday. He said: “At about 1 a.m., we heard a banging and crashing noise. Our dog started barking and going ballistic. He’s not the sort that usually barks. So we got the flashlight out to check. Our bedroom looks out the back, and we saw that the security light was on next door, but it calmed down, and we assumed it was nothing and went back to bed.

“The next morning, there was a big policeman on the doorstep. It’s really shocking. We have always found the family to be very nice.”

The house in Folkestone Road, which was being searched by forensic officers yesterday, has the Dar Al Uloom mosque and religious school just yards away.

The three-story house was one of at least five homes raided in the Walthamstow area as part of the investigation.

More than 20 officers descended on a Victorian house on Wednesday night, less than a mile away on Forest Road. The house was said to be empty, and no one was taken away.

A neighbor, John Weir, 50, said: “Police showed up at 10:30 in unmarked cars and blocked either end of the road.

“My daughter was talking to her boyfriend and saw four officers in uniform.They bashed open the door using a battering ram. I could see them go into the upstairs flat.

“They didn’t turn on the light, but they used torches to search the house.

“I assumed that nobody was home at the time because I didn’t see anyone being brought out.”

Forensic officers were still searching a fifth property on Queen’s Road last night, opposite the Masjid-e-Umar mosque.

It is believed that a man was arrested at the property on Wednesday night.

On Forest Road last night, police officers had cordoned off a large area of pavement and houses surrounding no. 386, while officers searched the first-floor flat.