The Iraqi prime minister has called for a national state of emergency after the city of Mosul and parts of the northern province of Nineveh fell to al-Qaeda-inspired fighters.
Nouri al-Maliki said on Tuesday that he would ask parliament to declare the emergency after the overnight takeoverby the Islamic State of Iraq and the Levant.
|Nouri al-Maliki, Iraqi prime minister
He said: "We will not allow Mosul to be under the banner of terrorism, We call on all international organisations to support Iraq and its stance in fighting terrorism. The entire world will suffer if terrorism spreads."
He stated that the government would arm civilians who volunteered "to defend the homeland and defeat terrorism".
Osama al-Nujaifi, the parliament speaker, said Iraqi soldiers abandoned their posts in Mosul when the attack began, action he described as "a dereliction of duty".
Nujaifi said parliament would discuss the call for a state of emergency on Thursday.
Reports by AFP later on Tuesday quoted Iraqi police sources as saying fighters had taken over areas of Kirkuk and Salaheddin province.
Syrian activists meanwhile said ISIL fighters had taken over the Syrian side of al-Yaroubiya crossing, one of three crossings into Iraq.
Al Jazeera cannot verify those reports.
Nujaifi, who is the brother of Atheel al-Nujaifi, the state governor, said he had asked the US ambassador in Baghdad for help in order to stop what he described as "a foreign invasion by ISIL".
A pro-ISIL Twitter feed said the group had released about 3,000 people from three prisons, although other estimates were lower.
Mosul is Iraq's second largest city, and the second city to be captured by fighters this year after Fallujah.
"We have lost Mosul this morning," a colonel at a local military command centre told the Reuters news agency. "Army and police forces left their positions and ISIL terrorists are in full control. It's a total collapse of the security forces."
Al Jazeera's Imran Khan, reporting from Baghdad, said Maliki faced opposition to his call for a state of emergency, which would grant him sweeping powers.
Khan said: "Many politicians have vocally criticised Maliki's handling of the crisis. Many in Iraq are asking why a lightly armed group like ISIL have been able to take over huge cities.
"Some here worry that a state of emergency will give Maliki sweeping powers that once he has, he may well find difficult to give up."