IRA Suspected in Killing of British Soldier : N. Ireland: It is the first political slaying in the province since the Anglo-Irish peace declaration.

LONDON —  A British soldier was killed by a suspected Irish Republican Army sniper in Northern Ireland on Thursday, dashing any hopes of a New Year’s cease-fire in the troubled province.

The slaying, which occurred in the republican-sympathizing border town of Crossmaglen, followed an IRA New Year’s message that made no mention of a cease-fire. The first political killing in the province since Britain and Ireland issued a joint declaration for peace on Dec. 15, it seemed to signal the IRA’s determination to continue its violent campaign to end British rule there.

The pact offered IRA supporters a place at the negotiating table if the group lays down its weapons.

Thursday’s attack was the fourth one on security forces in Ulster, as Northern Ireland is also known, in 12 hours and the ninth killing of a member of the military or police in the Crossmaglen area in two years.

Earlier Thursday, a soldier was slightly wounded in one of two mortar attacks in Belfast. A third mortar attack was thwarted.

And police and troops escaped unhurt in a land-mine explosion on the outskirts of West Belfast early Thursday.

The IRA ended a three-day Christmas truce on Monday.

Though the outlawed IRA has not rejected the Anglo-Irish peace declaration outright, a message Wednesday in the newspaper of Sinn Fein, the IRA’s legal political arm, declared that IRA resolve was unbroken. “Our struggle has endured and outlasted one British offensive after another. It remains solid. . . ,” the message said.

“The right of the Irish people to national self-determination and the question of lasting peace are inextricably linked.”

Seamus Mallon, deputy leader of Northern Ireland’s moderate, nationalist and mainly Catholic Social Democratic and Labor Party, said he was appalled by the slaying and that it posed serious questions about the IRA’s desire for peace.

“To have murdered so callously at a time when the prospects for peace are being explored does nothing but bring a wave of despair to the entire community,” Mallon said.

“To murder at this time when peace is being explored is cynical and offensive to everyone and can only add to the speculation that consideration of peace is not being given seriously by the IRA.”

John Fee, an SDLP City Council member in Crossmaglen, said the killing will cause grief at a time when peace hopes were high.

“It points to the enormous difficulty that the IRA have in actually coming to terms with doing away with their weaponry and the tactics they have been using for the last 25 years,” he said.

“I have no doubt at all that the bulk of people who traditionally support the republican movement were also hoping they were seeing the beginning of the end. Many will be asking why the IRA had to carry out this action. There are many throughout the nationalist and republican community who will be saying this shouldn’t have happened.”