Who's who

HIZB UT-TAHRIR (Islamic Liberation Party)

Described in the leaked Home Office/Foreign Office papers as a "structured extremist organisation", Hizb ut-Tahrir was founded in 1953, in Jerusalem, by a breakaway group of the Muslim Brotherhood.

The group is dedicated to the creation of a unified Islamic state (Khilafah) without national boundaries, which will be established by holy war (jihad) where it is necessary.

Its main activities in Britain were based on university campuses, until it was banned by the National Union of Students in the mid-1990s.

The group is banned in Germany and across the Middle East, but it has not been directly linked to terrorism. Its literature was found in the home of Omar Sharif, the failed British suicide bomber. Hut stated after the London bombings that "the rules of Islam do not allow the harming of innocent civilians" and it has condemned violence previously.

AL-MUHAJIROUN

The group, described in the government dossier as an "extremist organisation", was founded in Britain in 1996 as a breakaway organisation of Hizb-ut-tahrir.

It has a similar ideology to Hizb-ut-tahrir and its stated aim is the creation of a global islamic state - Khilafah. It believes that jihad in support of such a state is a duty.

It is also banned from university campuses, and most famously held a conference on the "Magnificant 19" - to "dignify and honour" those responsible for 9/11. It also praised the Madrid bombings.

According to the Government papers, the group has expressed views that Muslims should support jihad wherever it is taking place, including in Kashmir, Palestine and Chechnya.

The group was disbanded last October, but it is understood to have splintered in to numerous groups.

Concerns have also been raised about the Muslim Public Affairs Committee, which has an active student wing.