Northern Ireland police say they have seized two handguns, a shotgun and ammunition during house searches in a dissident IRA power base.

Friday's searches in the Irish Catholic end of the town of Lurgan are part of a wider police campaign to weaken the capabilities of IRA splinter groups following the April 2 killing of a 25-year-old policeman.

Police still are interrogating three men aged 40, 33 and 26 over the killing of Constable Ronan Kerr, who died when a booby-trap bomb exploded under his car. They have been in custody for a week without being charged. Belfast judges have extended their detentions a further week under British anti-terror laws.

Police last week seized a much larger arsenal of dissident IRA weapons hidden in stolen cars in a locked-up garage.