LONDON - British police have arrested three men and a woman in connection with the attacks on the United States last week.
"They were arrested in connection with the World Trade Center terrorist attack and are being questioned by Anti-Terrorist Branch officers," a Scotland Yard statement said.
A man, aged27 and a woman, 25 were arrested at a house in west London last night (NZT). A 29-year-old man was arrested later in the city of Birmingham, and was also taken to London for questioning, police said.
Metropolitan Police Commissioner John Stevens said that London was on the highest peacetime security alert in its history, with 1500 extra officers on the streets this weekend.
"London is at risk because it is one of the world's major capital cities, although there has been no specific threat," he said.
Britain has vowed to hunt down anyone associated with last week's devastating attacks on US landmarks who may be living in Britain.
Minister for Europe Peter Hain said intelligence was being shared with US investigators seeking those responsible for the suicide hijackings that killed thousands in New York, Washington and Pennsylvania.
The Daily Mail newspaper reported this week that five of the hijackers had trained in Britain, and that the FBI had passed names and details to British police.
The paper said "dozens of addresses across Britain will now be raided as police Special Branch and anti-terrorist officers try to trace the movements of the five and everyone they contacted".
A Scotland Yard spokeswoman declined to discuss the article.
