US troops were encountering little resistance as they moved on the town and were getting help from the local population, a US general said at the war command headquarters in Qatar.

Fifteen Tikrit tribal leaders called for an end to coalition bombardment of the city so a peaceful surrender of pro-Saddam militia there could be negotiated, one of them told AFP.

"We are ready to surrender, but let them stop their bombardments. After that we are asking for just two days to persuade the fedayeen (militia) to lay down their arms," Yussuf Abdul Aziz al Nassari said in company with a number of other tribal chiefs.

No militia or Iraqi troops could be seen in the centre of Tikrit, only a number of armed and extremely agitated residents, who said they wanted to prevent the looting that has occurred in every Iraqi city abandoned to the coalition by forces loyal to Saddam.

The residents, carrying Kalashnikov assault rifles and grenades, told AFP they would surrender to US forces, being led by the 1st Marine Expeditionary Force, if these were not accompanied by Iraqi opponents of Saddam's regime, notably Shiites and Kurds.

"Task Force Tripoli has moved north and is currently conducting operations in the vicinity of Tikrit," US Captain Frank Thorp said at Central Command in Qatar. "It is a significant force with significant firepower."

Tikrit, Saddam's traditional powerbase, lies about 180 kilometresmiles) north of Baghdad and is considered the last major city not under control of the coalition forces.

The area had been the target of more than a week of intense bombing, but it was not clear when US forces would seek to enter the city.

Tikrit and other parts of the north betweeen Baghdad and Kirkuk, where remnants of Iraqi forces were resisting, are now the main target of coalition forces, according to officials at the US war command centre.

The road into Tikrit from the northern city of Mosul was open Sunday, but had not been secured by coalition troops, an AFP correspondent said.

CNN television, whose reporters were shot at Sunday as they drove though a checkpoint on the edge of Tikrit, showed pictures of abandoned barracks of the Republican Guard outside the city.

In southern Iraq, the US-led forces were engaged in mop-up operations, US Major Rumi Nielson-Green said at Centcom.

US marines "entered Al Kut unopposed, they were assisted by contacts with local leaders," added Captain Frank Thorp.

A tip-off from local Iraqis also led to US troops finding "six or seven" US soldiers thought to have been taken prisoner by the Iraqis north of Baghdad, US military commander General Tommy Franks said. He added that they were in good shape.

In Basra, Iraq's second largest city, British army engineers abandoned their search for prisoners that locals said were trapped in underground cells beneath the bombed-out ruins of a prison complex. They found no-one.

In Baghdad, US forces tried to return the battered capital to normal after days of looting. They set up an operations centre to screen Iraqi workers and a Marines spokeswoman said they were seeking to put Iraqis back to work in key sectors, starting with the police and electrical power departments.

On Saturday, a marine was shot dead at a checkpoint outside a Baghdad clinic and one of the attackers, who carried a Syrian identity card, was also killed, according to Centcom.

Marines on Friday found more than 300 vests fitted for use by suicide bombers, it added.

Kurdish TV meanwhile reported that coalition forces had captured Saddam Hussein's half-brother Watban, who it said had served as his interior minister, as he attempted to cross the border into Syria.

In the northern city of Mosul, stretched US special forces turned to police officers of the ousted regime to stem ethnic clashes that have killed as many as 20 people.

The move threatened to complicate the US force's relations with Kurdish rebel allies who entered the city without a fight on Friday and for whom the mainly Sunni Arab police are a hated symbol of the old regime.

Meanwhile, peace began to return to Kirkuk, like Mosul a key northern oil city, following two days of looting after Kurdish peshmerga fighters seized the city almost unopposed on Thursday.

US soldiers began to arrive in the city on Friday after Turkey, which fears Kurdish dominance of the north would arouse separatist aspirations among its own Kurdish minority, secured a pledge from Washington to force the peshmergas out.

Turkish Foreign Minister Abdullah Gul said Sunday that Kurdish forces had withdrawn from both Kirkuk and Mosul in line with US assurances. But there was no immediate independent confirmation of this.

SPACE.WIRE