Police were remaining tight-lipped today about claims that the arrest of a Bradford man was linked to an al-Qaida plot to attack the Canadian Parlia-ment.

The 21-year-old, who was arrested at Manchester Airport on Tuesday night when he arrived on a flight from Pakistan, was still in custody today at an undisclosed police station in West Yorkshire.

His arrest, under the anti-terror laws, was followed by police raids on three houses in Hanover Square, Manningham, Bradford, and Otley Road, Barkerend, Bradford. They were followed by more raids yesterday in Dewsbury in which a 16-year-old boy was arrested.

A West Yorkshire police spokesman said the operation was "a continuation" of the operation at Manchester Airport but stressed it did not involve armed officers and was not connected to the Metropolitan Police operation in Forest Gate, London.

Canadian newspapers have linked the arrests to the ongoing investigation into an alleged "al-Qaida inspired" plot to storm the country's Parliament in Ottawa.

But one of them, The Toronto Star, said its police sources have not revealed what the connection is between the Bradford man and the suspects being held in Toronto.

Raids by armed officers of the Royal Canadian Mounted Police in Pickering, Ontario, on Friday and Saturday resulted in 17 suspected terrorists being detained.

Of these, 15 suspects appeared for a brief hearing on Tuesday and were remanded in custody for a week until their bail hearings begin. The other two suspects are already serving time in a Kingston penitentiary on weapons offences.

Canadian prosecutors have accused some of the suspects of plotting to storm Parliament, take hostages and behead the Prime Minister unless Canada withdrew its troops from Afghanistan, a lawyer for one of the suspects said.

West Yorkshire police would not comment on the reported links between the arrests in Bradford and Dewsbury and the alleged terrorist plot in Canada.

In Bradford yesterday a house at 27 Hanover Square, with a blue door splintered from the force of the battering ram, was being guarded by uniformed officers.

Residents said they were shocked by the raids. Asad Khan, 21, of Hanover Square, said: "We were sleeping and at 12.30am we heard a big bang and women screaming. The whole community got out. The police woke everyone up.

"The whole street was blocked off no one was allowed in or out. They were breaking down the door at number 27. I've known the boy that lives there all my life.

"We went to school together he is hard-working and supports his family. He was not extremely religious but had started to attend mosque and pray regularly."

Mohamed Amir lives a few doors away from 27 Hanover Square and was also at home when the raids happened.

He said: "There were about 20 police cars. This is a very close community and everybody knows everybody else.

"There was a loud noise last night and we all came out on to the street. Everybody is really shocked because nothing like this has ever happened here before."

Anwar Khan, 57, who has lived in street for 40 years, said it was a quiet neighbourhood, where children played in the street and residents kept their doors unlocked.

Mr Khan said: "Our doors are open and we have never had any bother."

He said the terror suspect had lived in the square all his life Dilnawaz Choudary, 33, said he had been shocked by the raids: "This is a very quiet area. The residents all support one another.

"We are hoping our children did not see this because it is not something we want them to grow up seeing."

The West Yorkshire police spokesman said no further arrests had been made during the raids in Bradford. He said occupants at the houses had been taken away and offered alternative accommodation while their properties were searched.

Councillor Shabir Hussain (Lab, Manningham) said he had been in touch with the family of the arrested man, whom he refused to name. He said they were staying with relatives.

Coun Hussain said: "They are obviously very distressed and have to be left alone while the investigation continues. They are wanting to keep a low profile.

"The man who was arrested had been to Pakistan three or four times in the last year but lots of people do that."