The Ulster Defence Association (UDA) is numerically the largest loyalist terrorist organisation with up to 5,000 members. It was recently declared "off ceasefire" because of repeated attacks on Catholic homes and churches with pipe- and firebombs. It is heavily involved in the drugs trade. Its members are heavily influenced by the extreme and volatile figure Johnny Adair, who is in prison.
The Ulster Volunteer Force (UVF) is smaller than the UDA but well equipped and better trained. It recently took part alongside the UDA in loyalist riots in north Belfast. They have an uneasy relationship following last year's bloody feud in which 14 loyalists died. The UVF supports the Belfast Agreement and David Trimble's stance on power-sharing government.
The Loyalist Volunteer Force (LVF) shot dead journalist Martin O'Hagan in Lurgan last month because he wrote about its drug-dealing. Formed by the popular though unpredictable figure Billy Wright, it is allied with the UDA and has funded arms deals through drug money.
The Orange Volunteers is small eccentric group behind a recent "Protestant rally" in Ballymena. This is believed to be a group of fundamentalists strongly opposed to the Belfast Agreement and any role for nationalists in the Northern government. It has no known armoury but has the capability to make pipe-bombs.