arch/ive/ief (2000 - 2005)

THE ground battle for the last stronghold of Saddam Hussein's regime could start as early as Monday.

The first elements of the US 4th Infantry Division, including 44 of the latest Abrams M1A2 tanks and 18 Paladin howitzers, will shortly be in attack position outside Tikrit, 112 miles north of Baghdad.

Intelligence sources said some of the missing regime members were now holed up in the town and that Iraqi forces might fight hard to protect them from an American assault. Iraqi military defences around Tikrit are being reinforced by surviving elements of the Republican Guard and by regular army units. This is the clearest sign yet that some of the regime leaders may be in the town.

Major-General Gene Renuart, a spokesman at US Central Command in Qatar, said: "Tikrit certainly is one of the key strongholds of the Baath party and it is an area that is important to us."

As part of the psychological build-up for an attack, General Renuart refused to rule out using the biggest weapon in the American arsenal, the so-called "Mother of all Bombs", or Moab (massive ordnance air blast bomb).

A Pentagon official was quoted on CNN as having confirmed that a Moab had been moved to an undisclosed forward base in the region. The Moab, which detonates 21,000lb of explosives above the ground, is dropped from a slow-moving C130 Hercules aircraft and is guided by the satellite-linked global positioning system.

The Moab, which can create temperatures of up to 538C (1,000F), is also designed to obliterate chemical or biological agents concealed in bunkers.

The heavily fortified town of Tikrit is thought to be one of the most likely sites in Iraq where Saddam could have hidden weapons of mass destruction in its complex bunker and tunnel system.