Kurdish fighters and US forces have been tightening their grip on the north of Iraq, taking control of the city of Mosul after the Iraqi army abandoned it.
Looted money was scattered across the streets of Mosul
US forces declared an overnight curfew in Mosul after a day of looting.
Like Kirkuk just 24-hours before, Mosul - Iraq's third largest city - fell without a fight, but crowds quickly went on the rampage, stripping public buildings and schools, and torching a central market.
The central bank was raided and people ran in grabbing handfuls of banknotes which were strewn over the streets as images of Saddam Hussein were defaced.
The US special forces commander in northern Iraq later announced a 2200 to 0600 curfew in the city.
Correspondents say coalition control over Kirkuk and Mosul will open up more avenues from which to attack Tikrit, whose people are bound to Saddam Hussein by tribal ties and are thought to be contemplating putting up fierce resistance.
Coalition aircraft have been striking Republican Guard positions in Tikrit, and roadblocks have
been erected to prevent Iraqi leaders from reaching the city to engage in fighting.
Kurdish withdrawal claim
A meeting on Friday between US military officials and Mosul's leaders on re-establishing authority in the city had to be postponed when gunfire broke out near the planned
site of the session.
Now about six small teams of US special forces have moved into the city centre and some regular peshmerga units been moved in to protect public properties, put up checkpoints and curb the looting.
But the presence of large numbers of Kurdish fighters in both Mosul and oil-rich Kirkuk has caused great consternation north of the border in Turkey.
On Friday a senior Kurdish official, Barham Saleh, said Kurdish militia have begun withdrawing from Kirkuk, but the BBC's Dumeetha Luthra says there is little evidence of change on the ground.
Earlier, the Turkish foreign minister, Abdullah Gul, said Turkish military observers, whom the US have invited into northern Iraq, would be arriving in Kirkuk shortly.
Ankara fears if the Kurds remain it could lead to an independent Kurdish state and inspire separatist demands among its own sizeable Kurdish minority.
In response Turkey has threatened to send its own troops across the border into northern Iraq.
Washington moved quickly to reassure Turkey that the Kurds would not be allowed to control Kirkuk and its oil resources, or to declare an independent state in northern Iraq.