Political parties have roundly condemned the assault in a bar in Derry last night on on the vice chairman of the North's Policing Board, Denis Bradley.
Mr Bradley pictured in 2002
The attack, blamed on dissident republicans, has been widely condemned by politicians from both sides.
Mr Bradley is not thought to have been seriously injured after the attack by at least one hooded man.
Police said this morning they were investigating the assault that happened in the Bluebell bar on Lecky Road in the Brandywell area of Derry.
"Anyone who was in the bar who witnessed the assault or has any information should contact police," a spokeswoman said.
Police who were at the scene of the attack at 10pm said they came under attack from a hostile crowd throwing petrol bombs and other missiles. One person was arrested and is due in court next month, the spokeswoman said.
Chief Supt Richard Russell later described what happened in the bar. "The man walked into the bar, approached Denis and hit him with something similar to a baseball bat.
"Denis was knocked down but we are not sure how many times he was struck.
"He suffered two lacerations to his head and a suspected broken nose.
"It was a vicious and brutal attack and really has to be condemned."
Chief Supt Russell said the suspect was wearing a light coloured hooded top and had a scarf around his face.
He added: "We don't think this is a random attack but it may have been an opportunistic attack.
One of the major lines of inquiry is in relation to dissident Republicans who have previously threatened Denis Bradley."
Mr Bradley is a founder member of the Bogside Community Association but has been the subject of threats from dissident republicans since joining the Policing Board. His family escaped a multiple petrol bomb attack last year.
SDLP leader Mark Durkan
A spokesman for Altnagelvin Hospital in Derry said Mr Bradley was in a stable condition.
Derry City football club had a home match at their ground last night and Mr Bradley, a fan, was watching the match with his teenage son when he was set upon.
SDLP leader Mark Durkan condemned what he said was a "vicious attack".
"Unlike his attackers, Denis Bradley argues his views openly, takes other opinions too and can justify his stance and his actions," Mr Durkan said.
"Attacking a man like this in this way proves the weak cowardice of its perpetrators.
"Nobody should suffer such an attack in any circumstances at the hands of any thug," he said.
Sinn Féin chief negotiatior Martin McGuinness visited Mr Bradley in hospital and said he unreservedly condemned the attack.
"I visited Denis in hospital last night. It was clear that he had suffered a vicious assault on his body. He was heavily bandaged and there were obvious signs of blood on his face. We spoke for about ten minutes and he told me he did not see the person who attacked him. His focus was on the television, he thought he had slipped and fallen. He was quite lucid and he told me that his primary concern was for his son who saw this attack on his father", he said.
Minister for Foreign Affairs Dermot Ahern said the perpetrators of the attack "belong to the past, in the same way as those who were involved in sectarian attacks and riots all summer belong to the past. They are enemies of all of the people of Ireland."
Mr Ahern said: "Denis Bradley is recognised across the community as a true Irish patriot who has worked tirelessly to achieve reconciliation on this island and whose personal courage and integrity has been an example to all.
Liz McManus of the Labour Party said she was "completely appalled".
"Denis Bradley stands for the humane type of new society all true democrats are attempting to create".
Sinn Féin chief negotiator Martin McGuinness, who visited Mr Bradley in hospital, said: "The attack on Denis Bradley was wrong and unacceptable and must be condemned.
"The fact that he is the vice-chairperson of the Policing Board does not warrant an attack on either him or his family.
"I am glad to hear that his injuries are not life-threatening and hope that he makes a full recovery."
The Ulster Unionist Party issued a joint statement on behalf of its Policing Board members, Fred Cobain, Alan McFarland, Lord Kilclooney and Sam Foster.
It read: "We strongly condemn this brutal and unjustifiable attack on our colleague on the Policing Board who was merely enjoying a quiet drink with his son in a bar when the attack happened.
"The police have confirmed the main suspects so far are dissident republicans.
"However, this is not the first time that they have targeted members of the Policing Board.
Alliance Party deputy leader Eileen Bell said: "This was not just a cowardly attack upon Denis Bradley as an individual, it is an attack upon the rights to build free speech and efforts to make a new beginning in policing.
"I wish Denis a speedy recovery, and know that this will not deter him one bit from speaking his mind, and making a contribution to a new Northern Ireland."
