Thousands of people are to attend a ‘Walk for Peace’ in Omagh tomorrow to mark the death of PSNI constable Ronan Kerr.

The idea for the walk grew out of a website set up in memory of the PSNI man, killed last Saturday when a bomb exploded under his car in Omagh.

Although no organisation has claimed responsibility, the attack is believed to have been carried out by dissident republicans.

One of the organisers, Barry Brown, said it will be non-party political and similar gatherings will be held in Belfast, Enniskillen and London’s Hyde Park.

He said: “This is very much a symbolic gesture to show that the people of Northern Ireland and of Omagh do not support the actions of those people and to show support for the family of Ronan.

“It is intended that people can come along and make their own gesture. There will be no banners on the parade and no organisations taking part, it will just be ordinary people standing in solidarity with Ronan’s family.”

The peace walk organiser said local people were still numb with shock at the policeman’s killing.

He said: “We want to stand united in shock and grief with the family of Ronan Kerr and to show our unity and solidarity, saying to the small minority in our communities who believe that terrorism and violence have a place in our society today that it has gone on for too long and we have come too far to let these people drag us back to the dark days of our past.”

Organisers expect between 6,000 to 10,000 people to take part in tomorrow’s marches and those attending are being asked to wear white ribbons to “symbolise their desire for peace”.

Last night a 33-year-old man was arrested in the Omagh area in connection with the killing.

Meanwhile, police have been given five extra days to question two men, aged 26 and 40, arrested earlier this week.

It has also emerged that police have set up a special unit to probe historical murders going back over 30 years. It is understood that this unit will also investigate more recent activities carried out by dissident republicans.

Police last night said they were having to deal with dissident republican threats against officers at a rate of one every two weeks.