The UN also said the humanitarian situation around Mosul, where up to 500,000 people have fled, was "dire and is worsening by the moment".Iraqi PM Nouri Maliki vowed to fight back against the Islamic State of Iraq and the Levant (ISIS) insurgents.He also said he would punish troops who fled offering little or no resistance.The militants are consolidating positions in Tikrit, Saddam Hussein's hometown, which they took on Tuesday, a day after capturing Mosul, Iraq's second city.ISIS, which is also known as ISIL, is an offshoot of al-Qaeda. It controls a large swathe of territory in eastern Syria and western and central Iraq, in a campaign to set up a Sunni militant enclave straddling the border.'Fighting devils'In a statement, the UN Security Council said it "deplored in the strongest terms the recent events in the city of Mosul".Secretary General Ban Ki-moon called on "the international community to unite in showing solidarity with Iraq as it confronts this serious security challenge".The Security Council also expressed "grave concern for the hundreds of thousands of individuals who have fled their homes".Earlier, Unicef's Iraq representative, Marzio Babille, said the situation in Mosul was "alarming"."The situation is dire and is worsening by the moment. We have to reach children with safe water, shelter, food, and protection - they cannot wait."The ISIS fighters swept south from Mosul through Baiji. Baiji hosts the nation's largest oil refinery but that appears to still be in government hands.The insurgents then moved into Tikrit.ISIS in IraqThe Islamic State of Iraq and the Levant (ISIS) has 3,000 to 5,000 fighters, and grew out of an al-Qaeda-linked organisation in IraqISIS has exploited the standoff between the Iraqi government and the minority Sunni Arab community, which complains that Shia PM Nouri Maliki is monopolising powerIt has already taken over Ramadi and Falluja, but taking over Mosul is a far greater feat than anything the movement has achieved so far, and will send shockwaves throughout the regionThe organisation is led by Abu Bakr al-Baghdadi - an obscure figure regarded as a battlefield commander and tactician. He was once the leader of al-Qaeda in Iraq, one of the groups that later became ISIS.One police captain there told Reuters: "Our forces were caught by surprise, they never expected ISIL would use police and army Humvee vehicles, we mistook them for government forces and it was too late to stop them."We are fighting devils and not ordinary people".A number of militants also reached the outskirts of Samarra, just 110km (68 miles) north of Baghdad.However, the government responded with air strikes and the militants were stopped from entering the city.ISIS said on Twitter it would "not stop this series of blessed invasions".The UN Security Council also "denounced the taking of hostages at the Turkish Consulate" in Mosul.Almost 50 Turks, including the head of the mission in Mosul, are being held by the militants, with Turkey's foreign minister warning there would be "harsh retaliation" if any of its citizens were harmed.Militants are reportedly travelling around the city telling citizens they are not in danger - even the Shia residents.One man who fled with his family told Reuters: "They told us not to be scared and that they came to liberate and free us from oppression. We are frightened because we don't know who they are."Foreign Minister Hoshyar Zebari said Iraq faced a "serious, mortal threat" and urged more cooperation between Baghdad and the Kurdistan regional government to combat the insurgents.Mr Maliki has asked Iraq's parliament to declare a state of emergency.In a live TV address, he said an unspecified "conspiracy" had taken place in Mosul and surrounding Nineveh province, causing security personnel to flee.He said: "Those who deserted and did not carry out their jobs properly should be punished."Mr Maliki told the people of Nineveh: "Do not give in. We are with you. Even if the battle is a long one, we will not let you down."ISIS has been informally controlling much of Nineveh for months, and in the past week has attacked other areas of western and northern Iraq, killing scores.The Iraqi government is struggling with a surge in sectarian violence that killed almost 800 people, including 603 civilians, in May alone.(BBC)Bakudaily.az