BELFAST, Northern Ireland -- Catholic politicians accused Northern Ireland's largest paramilitary group Tuesday of involvement in a thwarted bomb attack mounted by a Protestant extremist on the province's legislature.

The Ulster Defense Association, an outlawed anti-Catholic group with an estimated 3,000 members, denied any role in Friday's attack by Michael Stone, who was arrested and disarmed at the main entrance to the Northern Ireland Assembly. But Catholics said the UDA was the most likely source for the nail bombs found in a bag Stone was carrying.

The Police Service of Northern Ireland won a Belfast court order Tuesday compelling the three biggest broadcasters on the island of Ireland -- the British Broadcasting Corp. and Ulster Television in Belfast, and Radio Telefis Eireann in Dublin -- to hand over all their footage of Stone's attempt to breach security at Stormont Parliamentary Building.

Camera crews captured the moments when unarmed security guards pinned Stone, 51, into a revolving doorway, wrestled him to the ground and removed weapons from his jacket. The BBC and Radio Telefis Eireann confirmed they would hand over all their Stone-related footage to detectives Tuesday, while Ulster Television declined to comment.

Moderate Catholic politician Alban Maginness, a former Belfast mayor who has suffered UDA bomb attacks on his office, said the episode underscored the need for the UDA to disarm in line with the Irish Republican Army, the main Catholic-based paramilitary group.

The IRA surrendered its weapons cache last year in belated support of the 1998 Good Friday peace accord, but the UDA and other outlawed Protestant groups have refused to follow suit. The Good Friday deal had called on all paramilitary groups to disarm by 2000.

"The real point is that the UDA has not decommissioned a single bullet or ounce of explosives, and shows little intention of doing so. The UDA trained and nurtured Michael Stone and made him what he is," said Maginness.

But the UDA's commanders sought to distance themselves from Stone in a statement.

They said the UDA had tried to provide moral support to Stone after his 2000 parole from prison but said he grew distant as he pursued personal initiatives, including talking to IRA veterans and -- in a British television program -- to the widow and brother of a Catholic man he had helped to kill.

"This organization was not ready for this type of development, and Michael has since become more reclusive and withdrawn," the UDA said.

Britain has already rescinded Stone's parole for previous crimes because of his abortive attack on Stormont, where assembly leaders were debating the revival of a Catholic-Protestant administration, a major goal of peacemaking in this British territory.

Stone became an icon among Protestant extremists on March 16, 1988, when he launched a solo gun-and-grenade attack on an IRA funeral in Catholic west Belfast. He killed three people, including an IRA member, and wounded about 60 others before he ran out of bullets and grenades. Police rescued him from a mob beating by mourners.

A year later, he was convicted on six counts of murder for the cemetery attack and three other killings committed on behalf of the UDA, which killed more than 300 Catholics to try to terrorize the IRA's host community. The UDA called a cease-fire in 1994 but remains involved in violence, particularly in the course of defending its control of criminal rackets such as drug dealing, cigarette smuggling, CD and DVD piracy, counterfeiting and prostitution.

On Saturday, Stone was arraigned over the Stormont strike. He was charged with attempting to murder Gerry Adams and Martin McGuinness, leaders of the IRA-linked Sinn Fein party, as well as the two Stormont guards who stopped him. He also was charged with possessing nail bombs, an ax, a strangulation device and a fake handgun.