In the wake of one of the worst attacks on British troops in two decades of violence in Northern Ireland, Prime Minister Margaret Thatcher held urgent talks Saturday with her security chiefs to search for ways of combatting a fast-escalating IRA bombing campaign.

The Irish Republican Army claimed responsibility for the bomb that killed eight British soldiers and wounded 28 others early Saturday near the town of Omagh in the western part of the province.The soldiers were traveling in a civilian bus shortly after midnight on a straight, open stretch of road when the bomb blew the vehicle into a ditch, leaving a 6-foot crater in the roadway and parts of the bus and its human cargo strewn over a radius of more than 100 yards, according to witnesses.

In its statement, the IRA said the bomb contained 200 pounds of the Czech explosive, semtex.

"It was something I have never ever seen before and never ever want to see again," said Alan Rainey, a nearby resident who helped with rescue efforts.

Saturday's bomb caused the third largest loss of British Army lives in a single episode in Northern Ireland since British troops were first deployed there 19 years ago.

The IRA, whose support stems almost exclusively from Catholics, has launched sporadic campaigns over the past 70 years to wrest the province from British control and create a united, socialist Ireland.

The organization is outlawed in the Irish Republic as well as in Britain.

Saturday's bombing also marked the latest in a series of successful attacks against British troops mounted by the IRA in Western Europe, England and Northern Ireland that has left 26 soldiers dead so far this year - a death toll of British soldiers larger than the last five years combined.

After Saturday's bombing, Thatcher broke off her annual vacation in Cornwall to return to London for an emergency review of security measures with Lt. Gen. John Waters, commander of the 10,000 British soldiers stationed in Northern Ireland; provincial Police Chief John Herman, and her secretary of state for Northern Ireland, Tom King.

The circumstances of the latest bombing raised serious doubts about the security of British forces stationed there.

With the soldiers traveling in civilian clothes and their bus one of three civilian vehicles traveling together at fairly high speed in full darkness along the route, the IRA required detailed advance information in order to carry out the attack.

The Protestant member of Parliament for the Ulster area where Saturday's bomb went off, Ken Maginnis, along with two witnesses to the carnage, met with Thatcher to demand a return to internment.

At a news conference Saturday, King said only that internment, like other security measures, was under constant review.