Nouri Maliki acknowledged “vital areas” of the northern city had been seized.
Overnight, hundreds of men armed with rocket-propelled grenades and machine-guns seized the Nineveh provincial government’s offices in Mosul.
They also destroyed several police stations before overrunning the airport and army’s operations headquarters.
Elsewhere, a double bomb attack in the central town of Baqouba killed at least 20 people, police and medics said. The blasts, targeting a funeral procession in the capital of Diyala province, also wounded 28 people.
In the past week, the jihadist Islamic State in Iraq and the Levant (ISIS) and its allies have carried out major attacks on cities and towns in western and northern Iraq, killing scores of people.
Militants from ISIS have been informally controlling much of Nineveh province for months, imposing tolls of the movement of goods and demanding protection money from local officials.
After five days of fighting, they took control of key installations in Mosul, Iraq’s second largest city with an estimated population of 1.8 million.
PM Nouri Maliki, who is struggling to form a government in the wake of the April elections, has vowed to drive the ISIS “terrorists” out of mainly-Sunni Mosul in short order.
He is unlikely to succeed soon. He made similar vows when Sunni militants took over Falluja, west of Baghdad, in January, and they are still there.
It is not yet clear whether it is only ISIS involved in the Mosul takeover. In Falluja and its province, Anbar, Nouri Maliki has clearly alienated many Sunni tribesmen and others, creating fertile soil for the radicals.
Internet images of local youths and even children stoning Iraqi security vehicles as they fled Mosul suggest that the Shia PM is not popular there either.
ISIS is also actively fighting in neighboring eastern Syria to establish its control there, apparently aiming to straddle the border with an Islamic state.
If Nouri Maliki is to defeat the Sunni radicals, he may need the help of Kurdish forces from the north. That will come with a heavy price tag, and they have in any case so far refused.
On Monday, Nineveh Governor Atheel al-Nujaifi made a televised plea to the city’s residents, calling on them to “stand firm in their areas and to defend them against the strangers”.
He fled shortly before the provincial government’s headquarters fell to the onslaught late on Monday night.
On Tuesday, several residents told the Associated Press that black flags associated with jihadist groups were flying from buildings and that the militants had announced over loudspeaker that they had “come to liberate Mosul and would fight only those who attack them”.
Many police stations were reported to have been set on fire – local TV stations showed pictures of plumes of smoke rising over the city – and hundreds of detainees set free.
An interior ministry official admitted that police and soldiers had fled after removing their uniforms, telling the AFP news agency: “The city of Mosul is outside the control of the state and at the mercy of the militants.”
Osama al-Nujaifi, the speaker of parliament and brother of Nineveh’s governor, called on the Iraqi government and Kurdistan Regional Government to send reinforcements to Mosul to “fight the terrorists”, whom he said had seized military hardware, including helicopters.
Meanwhile, the Turkish consulate in Mosul confirmed reports that 28 Turkish lorry drivers had been abducted by militants in Nineveh.
BDp7kj90KKkImage source: Wikimedia Commons President-elect Donald Trump celebrated his election victory at the Ultimate Fighting…
Millions of voters across the US chose to return Donald Trump to the White House…
Donald Trump declares victory in the US election as he addresses jubilant supporters in Florida.…
Stocks around the world are rising as Donald Trump appears to be on the cusp…
Donald Trump has won Pennsylvania, North Carolina and Georgia and taken a lead over Kamala…
Quincy Jones, the celebrated musician and producer who worked with Michael Jackson, Frank Sinatra, Ray…