PORTADOWN, Northern Ireland The British Army was out in strength in Portadown to the west of Belfast on Saturday on the eve of the controversial Drumcree parade, the climax of Northern Ireland's Protestant marching season.

Some 2,200 soldiers were mobilized, in an attempt to cope with the kind of violence that has been seen for the past three years during the parade, which has sparked violent clashes between Catholics and Protestants.

Six hundred soldiers begun erecting an enormous metal barricade at dawn Saturday, blocking access to a bridge to stop Protestant marchers from entering the mainly nationalist area of the town at Garvaghy Road in Portadown, which has been declared out of bounds.

They also installed barbed wire in surrounding fields and enlarged a water-filled ditch.

For the fourth year running the parades commission has banned Orangemen from using the Garvaghy Road route for the return leg of their parade, following rising tensions in the province during the past month.

The marches are held every year to commemorate past Protestant victories over Roman Catholics.

As centuries have passed since the historical battles, Catholics argue that marches are out of date and needlessly provocative.

Protestants say they are a demonstration of their culture and heritage and that it is their inalienable right to march on public roads.

Two weeks ago Northern Ireland saw its worst sectarian violence for three years.

During one night of troubles, dozens of people and some 60 police officers were injured as loyalists and nationalists clashed in north and west Belfast.

The British and Irish prime ministers, Tony Blair and Bertie Ahern, will head negotiations with parties from Northern Ireland in Birmingham on Monday and Tuesday.