Prime Minister John Major, expressing contempt for the Irish Republican Army, praised the "stoicism and good humor" of the traveling public, which struggled all morning with citywide traffic snarls. No bombs were found.
"It is essential to take these warnings seriously," Major said. "The IRA have murdered in the past. They will not hesitate to murder again."
No one claimed responsibility, although the people who called in the threats used recognized IRA code words.
"It's a clear attempt by the IRA to disrupt the British general election" on May 1, said Tony Blair, leader of the Labor Party, which is way ahead in the polls.
In late March, Labor's Northern Ireland spokesperson, Mo Mowlam, suggested that the Sinn Fein party could be invited to join all-party talks in Northern Ireland in June if their allies in the IRA quickly restored their cease-fire, which lasted 17 months until February 1996.
The IRA's answer was more disruption and violence: a bomb hoax that canceled the Grand National horse race on April 5, the shooting of a police officer in Londonderry, Northern Ireland, on April 10, and a bomb Friday at the railroad station in Leeds.
Yesterday's threats forced the evacuation of four major railroad stations and two airports.
"Basically, west London and central London are closed," Royal Automobile Club spokesperson Peter Brill said at midmorning. "This is going to be some of the worst traffic chaos that we have seen in London for many years, if ever."
Police sealed off Trafalgar Square and Whitehall, at the heart of the British government. Cars, taxis and buses, wedged bumper to bumper, strangled Parliament Square. Some roads into the city were clogged solid.
Thousands of passengers were stranded out on the tarmac at Gatwick and Luton airports before they received clearance to disembark. Others waited for hours, their flights canceled or re-routed.
The railroad stations all reopened by noon, and the gridlock slowly melted. Flight disruptions, however, lasted all day.
Some people caught in the mess took the bomb threats in stride. Others were exasperated.
"I don't think anyone's going to take any notice of them; it's happened time and time again," said Ian Baker, waiting for police to give the all-clear to enter the building where he works.
"It's John Major's fault,' said Mike Fenton, who spent three hours driving nine miles into central London. "If he had sorted out the problem in the beginning, we wouldn't have this problem. ... I hope (Labor) will negotiate with the IRA and we'll get on with life as normal."