Schools across Northern Ireland are expected to close today as teachers attend rallies protesting against death threats made by loyalist paramilitaries. The protest received the full backing of Northern Ireland Secretary John Reid.

Widespread condemnation from politicians and union leaders followed a statement last week by the Red Hand Defenders naming teachers as “legitimate targets”.

The same paramilitary group, a cover name for the Ulster Defence Association and the Ulster Freedom Fighters (UFF), later claimed responsibility for the killing of a young postal worker in north Belfast.

Teachers unions are supporting a call from the Irish Congress of Trade Unions (ICTU) for workers to stage a half-day strike today.

Thousands are expected to attend a rally at Belfast City Hall and other rallies across the region. Tom McKee, regional officer of the National Association of Schoolmasters Union of Women Teachers, urged members to attend “what is one of the most important rallies ever held in Northern Ireland”. He said: “There must be a clear message given to the paramilitaries that no group has the right to determine who will work and who will not work, who will live and who will not live.”

Frank Bunting, chairman of the Northern Ireland Teachers Council, said the hundreds of teachers who turned up for work despite the death threats were “heroes”.

Most of the 25 Catholic schools situated in predominantly Protestant areas of north Belfast reported nearly 100 per cent attendance of teachers and ancillary staff.

But some delegates at a meeting of NASUWT representatives in Belfast declared that “the situation has become almost unbearable”.

The death threats follow more rioting at Holy Cross primary last week, which for the first time forced the closure of the school last Thursday, and an attack on teachers’ cars at the nearby Our Lady of Mercy secondary.

Loyalist paramilitary gang members, one wielding a gun, ran into the school car park at 11am and attacked 18 cars with iron bars.

Teachers’ union leaders stressed that the death threat affected teachers of all denominations as it would inevitably lead to retaliatory action from nationalist paramilitaries.

On Monday a Protestant secondary, the Boys’ Model in north Belfast, was evacuated following a bomb threat. The same day two Catholic schools were the victims of arson attacks.

By Wednesday the UFF issued a statement saying it unreservedly condemned the threats against teachers and postal workers.

Mr McKee welcomed the condemnation, but added: “The teachers’ unions and the ICTU do not regard this statement as a restoration of normality.”

Teachers’ unions and the ICTU have agreed that all staff involved in invigilating external examinations on Friday afternoon should report for work as normal.