A car bomb exploded in a staunchly pro-British Protestant town Monday, a few hours after peace talks on Northern Ireland's future resumed.

Police said no injuries were reported from the blast in Portadown, 30 miles southwest of Belfast, but one building was badly damaged by fire."Flames are shooting into the sky. . . . I have seen people in tears, people are shocked and stunned," said Portadown Mayor Kenneth Twydle.

Several telephoned warnings to Belfast media allowed police to evacuate nearby streets before the explosion.

In Belfast, peace negotiations resumed Monday with the IRA-allied Sinn Fein party excluded because of two killings this month blamed on the Irish Republican Army.

David Trimble, leader of the largest Protestant party, the Ulster Unionists, said the bombing "underscored the silliness" of plans to let Sinn Fein return to the talks within two weeks.

Trimble, who represents Portadown in the British Parliament, said an unclaimed car-bomb attack on one Protestant town Friday and the bombing today are "the IRA's response to the conduct of the talks."

Brid Rodgers, a Roman Catholic and local official in the Portadown area, said attacking Portadown "appears to have been designed to cause maximum provocation and to draw other extremists into a response against the north's innocent Catholic population."

Sinn Fein is demanding to meet with British Prime Minister Tony Blair, and says that otherwise it might not return to the talks March 9, the date specified by the governments. Blair's Downing Street office said he was considering their request.

But Ulster Unionist negotiator Ken Maginnis said a Blair-Sinn Fein meeting now during the "quarantine period" would "fatally undermine" the negotiating effort.

"If the prime minister leads a gutless government then of course he may well bow to the dictates of Sinn Fein-IRA," Maginnis said.

A Protestant party today was readmittted to the negotiations at Stormont, the center of British administration for Northern Ireland where the talks began in June 1996.

The Ulster Democratic Party was barred four weeks ago after the pro-British paramilitary group it represents, the Ulster Defense Association, admitted killing Catholics in violation of its own October 1994 truce.

Former U.S. Sen. George Mitchell, chairman of the talks, requires all participants to adhere to a code of nonviolence or risk indefinite exclusion.

Ulster Democrats leader Gary McMichael said the governments were "running scared" of the possibility that the IRA might resume full-scale bloodshed in Northern Ireland and Britain. He said Sinn Fein should have been excluded for at least as long as his own party.

A few hours before the talks resumed, Irish soldiers defused a crude car bomb that had been abandoned outside a police station near the Irish Republic's border with Northern Ireland.

No group claimed responsibility for abandoning the car, which contained a drum full of gasoline. Police evacuated about 1,000 people from a nearby hotel and nightclub and closed the main road between Dublin and Belfast for several hours.