DUBLIN (AP) — Police arrested seven suspected Irish Republican Army dissidents Wednesday on suspicion of involvement in a wave of bomb attacks this year in the British territory of Northern Ireland.

The Police Service of Northern Ireland said it arrested three men in the border town of Newry and two others in or near the province's second-largest city of Londonderry. The Garda Siochana police force in the neighboring Republic of Ireland said its officers arrested two men in the same investigation.

Hours earlier a pipe-bomb had exploded — the latest of the attacks — outside the police base in the religiously polarized town of Lurgan. The overnight blast damaged a building across the street, but injured nobody.

Northern Ireland police have been on high alert amid fears that IRA splinter groups could mount a major bombing in the hours surrounding the United Kingdom's parliamentary elections Thursday. Northern Ireland elects 18 members to the House of Commons in London.

Security analysts said Wednesday's arrests could be designed to keep key dissident personnel behind bars over the weekend. Under British anti-terror laws, suspects can be held without charge for weeks.

The dissidents' violence is already on the rise. Last month they detonated two car bombs outside the Northern Ireland office of the British spy agency MI5 and a police station in the border village of Newtownhamilton. Neither blast caused damage or serious injuries.

The dissidents seek to wreck the IRA's 1997 cease-fire and the Catholic-Protestant government in Northern Ireland, the cornerstone of the U.S.-brokered Good Friday peace accord.