Suspected IRA dissidents and their supporters hijacked cars last night in working-class Catholic areas of Northern Ireland in a co-ordinated effort to block roads and threaten police stations, police said.

Suspected IRA dissidents and their supporters hijacked cars last night in working-class Catholic areas of Northern Ireland in a co-ordinated effort to block roads and threaten police stations, police said.

The Police Service of Northern Ireland said it had received a wave of reports of vehicles being hijacked by masked gunmen in several parts of Belfast and in the Kilwilkie district of Lurgan, a power base for Irish Republican Army dissidents, southwest of Belfast.

Some vehicles were set on fire in roads to disrupt traffic at rush hour, while others were abandoned near four Belfast police stations and on Northern Ireland's major motorway near Lurgan.

Police said they were treating all the abandoned vehicles as potential car bombs, although they cautioned this was unlikely. They urged motorists to avoid Kilwilkie and parts of Catholic west Belfast.

Yesterday's upheaval came at the end of a month in which IRA dissidents shot to death two soldiers and a policeman - the first killings of British security forces since 1998, the year of Northern Ireland's peace accord.

Police said at least two cars were hijacked in Lurgan's Kilwilkie district, the power base of suspected IRA dissident Colin Duffy. Duffy, 41, was charged last week with murdering the two soldiers.

One of the hijacked cars was abandoned on the M1 motorway, which connects Belfast to Dublin, 100 miles to the south. Authorities shut part of the motorway as a precaution.

One abandoned vehicle was left near the Stormont Parliamentary Building, the centre of Northern Ireland's power-sharing government.

The coalition's Protestant leader, First Minister Peter Robinson, said the rising dissident IRA threat would not spur Protestants to sever links with Sinn Fein, the IRA-linked party that represents most Catholics today.