Police arrested two Belfast men Friday on suspicion of involvement in this week's attempted assassination of a prominent member of an outlawed Protestant group, the Ulster Volunteer Force.

Mark Haddock, 36, was shot several times at close range Tuesday as he met other Protestant militants on the edge of north Belfast. His condition improved Friday at Belfast's Royal Victoria Hospital, where he was removed from the critical list.

The Police Service of Northern Ireland said its officers arrested two men in different Protestant parts of Belfast to be questioned about possible involvement in the shooting of Haddock. Both suspects, whom police declined to identify, were detained at the police's main interrogation center in Antrim, west of Belfast, where under British anti-terrorist law they could be held for up to two weeks before being charged or released.

Haddock, who is currently on bail while facing a charge of trying to murder a Protestant bar bouncer, is suspected of working as a paid police informer within the ranks of the UVF, an outlawed anti-Catholic gang that is supposed to be observing a 1994 cease-fire in support of Northern Ireland's 1998 peace accord. Usually, members of any outlawed paramilitary group suspected of passing information to police risk being executed by their colleagues.