PRESIDENT Bush was today visiting the remains of the World Trade Centre as America bowed its head in a day of prayer.

He was due to tour the site of the collapsed twin towers and meet rescue workers who have laboured round the clock to find survivors and recover the dead.

His visit to the worst of the three sites of devastation, where up to 20,000 may have died and already almost 5,000 have been officially listed as missing, comes on what Mr Bush has called "a national day of prayers and remembrance". The president was to attend a prayer service in Washington, where around 190 are missing, presumed dead, in the part of the Pentagon into which one of the four hijacked jets flew.

Combined with the deaths on the four hijacked planes, the grim toll has already reached 5,000, making it the worst day of death in American history.

Mr Bush was urging people to "attend prayer services at churches, synagogues, mosques, other places of their choosing to pray for our nation, to pray for the families of those who were victimised by this act of terrorism", his spokesman said.

And the visit comes after a day of shattered hope in the smouldering ruins of the two collapsed towers, as the belief that five firefighters had survived in the rubble since Tuesday turned out to be a misunderstanding.