ty. Police sources said they landed inside perimeter fences at the Willowfield and Ballynafeigh stations in the heart of Protestant east Belfast. Last week a small Irish republican guerrilla group, the Irish National Liberation Army, admitted to failed grenade attacks on two police bases elsewhere in the British-ruled province. Thursday`s alerts came just hours after pro-British Protestant and pro-Irish Catholic parties ended 16 months of wrangling and launched a crucial phase of negotiations on the political future of Northern Ireland. Irish Republican Army (IRA) guerrillas called a ceasefire in their 28-year war against British rule in July but a splinter group, the Continuity IRA, exploded a huge bomb in a country town last week. The Continuity IRA and INLA are opposed to current peace talks.