US Brig Gen Vincent Brooks singled out Tikrit yesterday as one of the last Iraqi "strongholds".

Saddam could flee to his birthplace, hoping its die-hard tribesmen with blood-ties will fight to their deaths to protect their leader. And even if Saddam is already dead, some fear Tikrit will remain a hotbed of resistance fighting long after a new government is installed in Baghdad.

The town owes a lot to Saddam. Before his Baath Party came to power in 1968, it was an isolated backwater. 

But thanks to huge government investment in infrastructure and business, Tikrit has grown into a sprawling town of some 260,000 people. Tikrit now hosts a huge army garrison for the Republican Guard, Iraq's best-trained troops, as well as an air base and air force academy.

Saddam has also sprinkled the town with some of his largest and most elaborate presidential compounds. And if he went into hiding there, he could easily vanish in the labyrinth of tunnels believed to be linking those sites to the eastern banks of the nearby Tigris River.

Brooks said neutralising Tikrit is an important step in breaking Saddam's power base, even as coalition forces swarmed through Baghdad, raided presidential palaces in the capital and delivered a strategic airstrike meant to kill Saddam, his two sons and other top Iraqi leaders.

"Tikrit is one of the areas we know is a stronghold for the regime leadership," Brooks said. "Tikrit has not escaped our interest; nor has it escaped our targeting."

Brooks said coalition forces are already hitting "command and control" facilities there, but wouldn't go into details "since operations are ongoing".

Special operations forces have already been watching the roads leading some 140km north out of Baghdad to the city. They want to block Saddam, if he is still alive, from stealing away to his birthplace and prevent Republican Guard remnants from regrouping there.

The Patriotic Union of Kurdistan, one of two main Iraqi Kurdish groups opposing Saddam, claimed yesterday that Saddam already was hiding in Tikrit. 

The party's newspaper said Saddam, his two sons and many of his top aides moved to Tikrit after fighting intensified in Baghdad.

How much resistance Tikrit can muster, though, is unknown.

Brooks said yesterday that many of the Iraqi forces stationed in the city in the war's early days have since moved south and engaged in combat elsewhere.

Still, Tikrit is also a Baath Party power centre for Sunni Arab tribes. Fearing a loss of influence in a new Iraq possibly run by the country's Shi'ite majority, they may try holding out for as long as possible.

And if Saddam goes into hiding there, he may be able to organise clandestine cells and launch a guerrilla war against US troops similar to the one his Baath party waged in the 1950s.

"It is entirely possible that some residual elements of the Baath Party will reconstitute themselves as an underground revolutionary armed-struggle party that will launch terrorist attacks against US forces and the interim authority," said John Pike, a military analyst at GlobalSecurity.org.

"Pacifying Tikrit is going to be a particular problem," he said.

In the Baath Party's early days, Saddam rose to fame in 1959 by participating in a failed assassination attempt on then-Prime Minister Gen Abdel-Karim Kassem. Even back then, Tikrit served him well. After the botched assassination attempt, the young Saddam fled town on horseback across the lonely desert for neighbouring Syria.