A spate of violence in Saddam Hussein's heartland north and west of Baghdad yesterday showed that his capture offered no quick fix to Iraq's woes.
In Falluja, US troops killed an Iraqi, who they said had fired a grenade at them after they broke up a second day of riots protesting against Saddam's humiliating capture in a dirt hole on Saturday.
Rioters had swarmed towards the US-appointed mayor's office, forcing local police to retreat before troops moved in.
US troops killed 11 of what they described as Saddam loyalists who tried to ambush them in Samarra on Monday, and also killed five Iraqis in Falluja and nearby Ramadi overnight yesterday after coming under fire in riots.
In Tikrit, Saddam's home town near which he was caught following a tip-off, a roadside bomb wounded three US soldiers yesterday.
Tanks rolled on to the streets of Tikrit as a message that the US army would not tolerate shows of support for Saddam.
US troops broke up at least four attempted pro-Saddam demonstrations, and three soldiers were wounded when a bomb went off as their Humvee patrolled the streets.
In response, 30 American tanks and Bradley armoured vehicles rolled up Tikrit's busy main street, while two helicopter gunships buzzed overhead.
Armed troops jumped down from tanks and some used strong language to clear shoppers from crowded pavements in a town smarting from lost privilege after the fall of Saddam.
Tikrit is home to many of Saddam's kinsmen, who enjoyed wealth and status under his three- decade rule. "These people love Saddam, that isn't true of other cities," said Lieut Col Steven Russell.
"These people have always hated us in this area. It is not surprising that they hate us."
Some locals backed into shop doorways, many just stood and watched the parade by an occupying army, whose temporary base is a complex of palaces Saddam built for himself and his family on the bank of the Tigris river on the edge of town.
An hour later, a handful of military vehicles returned, one carrying the US-backed regional governor Mr Hussein al-Jaburi, while a recording of his voice boomed a warning to would-be Saddam loyalists.
"Any demonstration against the government or coalition forces will be fired upon," Mr Jaburi's voice said, according to an army interpreter. "This is a fair warning."
Demonstrators risk a year in jail and, if they work for the state as civil servants or teachers, they will lose their jobs, the message said. All demonstrations are illegal in the US-occupied province.
"They are not allowed to go around kissing pictures of Saddam in this city," Lieut Col Russell said. "It will not happen."
Afterwards, Mr Jaburi and Lieut Col Russell interviewed a middle-aged man in traditional Arab clothing, who they suspect of inciting demonstrations.
"Look me in the eye. Let me make something very clear," the American officer told the man over tea at the governor's office.
"If our ears and eyes see and hear you are connected with demonstrations, and anti-coalition activities you will be going to jail for a very long time."
Lieut Col Russell described the roll-out of tanks not as a show of force, but as a security operation and said a tough approach was needed. "We cannot hand out lollipops, it does not work," he said.
Meanwhile, dozens of Iranians arrested in Iraq in recent months have returned to Iran after being released by US forces.
The state television in Iran said 41 returning Iranians were greeted by Iranian officials.
"They kept us in custody for four months without providing any reason for our arrest," one of the returnees was quoted as saying.
State television said those returning from Iraq comprised 36 people who had gone to provide humanitarian assistance to Iraqis after the war and five pilgrims hoping to visit Shia Muslim sites.
The British Prime Minister, Mr Tony Blair, said yesterday he hoped Saddam might now lift the lid on his illegal weapons programme.
Asked in an interview if Saddam's capture could yield a breakthrough in the hunt for the banned arms, he said: "There's obviously that possibility there, but I think in any event we have got to carry on doing the work we're doing."