LONDON (AP) _ The Irish Republican Army claimed responsibility today for a bombing that shook a London business district and chilled hopes for a durable peace in Northern Ireland.

One body was found in the rubble this afternoon, police said, but they could not immediately say whether it was a man or a woman.

The bomb exploded Friday night in a parking garage in the Docklands area of east London, one hour after the unexpected announcement that the IRA was calling off a 17-month cease fire to protest the slow pace of the peace process. At least 36 people were injured.

The IRA accused the British government of sabotaging the peace process by stalling on all-party negotiations, but President Clinton and Irish Prime Minister John Bruton joined the British in condemning the attack.

The bombers' political allies, caught by surprise, pleaded today for urgent meetings with the British and Irish governments.

``I had no prior knowledge of what was going to happen,'' said Gerry Adams, president of the IRA-allied Sinn Fein.

``Following last night's events, I am now seeking urgent meetings with the British and Irish governments,'' Adams said in a statement issued in Belfast, capital of Northern Ireland.

Britain gave no immediate answer, although both the British and Irish governments said Friday the attack would not stop them from seeking peace in the British-ruled province.

Rescue workers continued today to search the buildings wrecked by a bomb that Scotland Yard police commissioner Sir Paul Condon said contained up to half a ton of homemade explosives.

London Weekend Television said two people were feared missing in the rubble, and the London Fire and Civil Defense Authority confirmed that not everyone had been accounted for.

In daylight the full extent of the damage appeared far worse than originally feared. Twisted pipes, crumbled concrete and glass from five badly damaged buildings near Canary Wharf Tower, Britain's tallest high rise in London's Docklands, littered streets.

Heavily armed police were stopping cars and trucks in London, and trash bins were hastily removed from railway stations so they could not be used to hide explosives.

British troops reappeared in flak jackets on Belfast streets immediately after the 7 p.m. (2 p.m. EST) explosion. They sealed off roads around the airport and mounted street checkpoints _ all depressingly familiar sights in the sectarian-divided British province. The patrols had been withdrawn after the IRA cease-fire which started Sept. 1, 1994.

In Washington, President Clinton called the bombing ``terrible and cowardly and said today he will do all in his power ``to make sure the enemies of peace do not prevail.''

``This attack was aimed at the growing prospects for peace, a just and lasting peace,'' he said.

Bruton today demanded that the IRA and Sinn Fein promise unequivocally to forswear violence for good.

``It must stop. It must stop permanently because if we are to restore the momentum of the peace process there cannot be the constant looking over the shoulder,'' Bruton said before an emergency Cabinet meeting in Dublin.

Queen Elizabeth II, using unusually strong language, condemned ``this sickening act of violence.''

``This is a very grave as well as a very wicked and disgusting episode,'' said Sir Patrick Mayhew, the British Cabinet minister responsible for Northern Ireland. ``And although it doesn't prevent one from being hopeful, it does make it more difficult to be hopeful.''

The IRA claimed responsibility for the bombing today in a telephone call to Ireland's RTE broadcasting service. Blaming British foot-dragging over peace talks, the IRA called the same network Friday to announce it was aborting the cease-fire just an hour before the bomb exploded near Canary Wharf Tower.

``Instead of embracing the peace process, the British government acted in bad faith,'' the IRA statement said.

``The blame for the failure thus far of the Irish peace process lies squarely with John Major and his government,'' it said.

Peace negotiations have stalled in recent weeks over demands by British Prime Minister John Major and Northern Ireland Protestants that the Catholic-based IRA start handing over its weapons before all-party negotiations.

A commission headed by Senator George Mitchell, D-Maine, met with the various sides in the Northern Ireland conflict recently and recommended Britain soften its stance. But that has not happened.

Today, the IRA also blamed British security services for the injuries called by the blast. The caller said the ``regrettable injuries'' could have been avoided if security forces had acted promptly on an IRA warning.

The IRA cease-fire had halted its long bomb-and-bullet campaign against British rule in which nearly 3,200 people died. Protestant paramilitary groups, who responded by calling their own cease-fire, gave no immediate indication whether they will resume violence.

The blast, which partially demolished a six-story building and damaged a commuter rail station, South Quay, reverberated four miles across London, blowing out windows in offices and apartments. Blood-splattered people streamed out of pubs and offices and some collapsed on sidewalks.

Police said they received a warning with a recognized IRA codeword and were still trying to clear the train station when the bomb went off.