In the past two decades the IRA has developed a range of improvised
and imported weaponry, including mortars, grenades, guns (such as
AR-15 Armalite and AK-47 Kalashnikov rifles), rocket launchers,
and bombs (ranging from small devices sent in the mail-letter bombs
- to lorry bombs large enough to destroy several multi-storey buildings).
Relying upon committed sympathisers in Ireland, Northern Ireland,
and other parts of the Britain for funding, local intelligence,
and safe houses, attacks are carried out by small operational cells
of two to five members and are known as Active Service Units.
IRA members, known as Volunteers, are concentrated in Northern
Ireland, particulary in the south Armagh county, although a smaller
number are based in the Republic of Ireland; there are also small
cells in the rest of the Britain. The current hard-core membership
of the IRA is estimated at about 400. IRA cells have also operated
from time to time in the United States and other overseas locations.
A new kind of Volunteer has been recruited in recent years: the
university-educated computer expert who can construct advanced electronic
detonators and sophisticated timing and remote-control mechanisms
for use in bombs and mortars, particularly driverless car bombs.