Conditions on the seabed have been hazardous throughout

Russian officials have repeatedly denied that the operation timetable has slipped badly, insisting that time for hitches had been built into the schedule.

Now the holes have been cut, the next stage of the salvage operation will involve cutting off the forward section, which may contain live torpedos and is considered too dangerous to raise.

A barge carrying equipment for the cutting operation was nearing the salvage site after setting sail from the Norwegian port of Kirkenes, officials said.

It is expected to arrive on Wednesday.

If that stage suceeds, giant steel cables will be attached to the 26 holes and the vessel reeled in to the surface.

For relatives, the agony goes on

Fears remain among environmentalists that disturbing the wreck, with its unexploded munitions and nuclear reactor, could prove highly risky.

But President Vladimir Putin has insisted that the operation will go ahead to discover exactly what caused the tragedy.

The Kursk sank when explosions tore open the forward section. The entire crew of 118 died, although some lived long enough to write farewell notes to their families.

The remains of the crew members will be removed from the Kursk and buried on land.