Northern Ireland police have seized a shoulder-fired rocket launcher and an armor-piercing warhead during a raid on a house in Catholic west Belfast, a power base for Irish Republican Army splinter groups opposed to the British territory's peace process.

Tuesday night's discovery renewed questions over how much of the Provisional IRA weapons arsenal fell into the hands of dissident members in advance of the dominant IRA faction's 2005 decision to renounce violence and disarm. Previous attacks since 2005 have demonstrated that the die-hards retained control of some consignments of the Provisionals' prized Semtex explosive.

The well-worn weapon that police put on display Wednesday was a Russian-designed RPG-7, a bazooka-style rocket launcher that has been popular with militaries and rebel movements worldwide since the 1960s.

The one seized is believed to date back to the Provisional IRA's mass importation of mostly Soviet-made weapons supplied by Libyan dictator Moammar Gadhafi in the mid-1980s. The Provisional IRA kept most of those Libyan arms, including tons of Semtex and dozens of RPGs, hidden in rural bunkers until they were destroyed by international arms inspectors in 2005.

Police evacuated families from about 10 neighboring homes overnight as British army experts examined the warhead. They arrested nobody at the house, which was unoccupied.

Police in both parts of Ireland have used paid informers and electronic surveillance to track the plans of several small IRA factions that continue to mount occasional bomb and gun attacks in Northern Ireland. Most of their attacks fail either because their weapons malfunction or police intervene before the attack can be launched.

These small IRA factions have made attacking police a top priority, but officers still often use armored vehicles when operating in hard-line Irish nationalist parts of Northern Ireland, making armor-piercing weapons essential.

The police have typically demonstrated they are one step ahead of IRA dissidents, repeatedly seizing weapons systems -- both RPGs and move devastating horizontal mortars -- before they can be used to blast a passing vehicle. Unlike RPGs, which have to be aimed and fired like a rifle, the homemade mortars can be hidden by the side of a road and fired by remote control.

On Feb. 8, police in the Republic of Ireland found two vehicles in County Tipperary carrying three RPGs and warheads. Two men were charged in connection with that seizure.

The Provisional IRA's regular use of RPG-7s in attacks on police and army vehicles, watchtowers and bases is memorialized today in Catholic west Belfast, where one street since the 1980s has been unofficially named "RPG Avenue."