Islamist forces on Wednesday stormed the Turkish consulate in the northern Iraqi city of Mosul and took diplomats captive, a day after the Islamist State of Iraq and the Levant routed government forces.

The jihadists fighters kidnapped Consul Öztürk Yılmaz, head of the diplomatic mission, and 24 staff members, a police colonel said.

“ISIL members managed to kidnap the Turkish consul and 24 of his guards and assistants,” the officer said, referring to powerful jihadist group the Islamic State of Iraq and the Levant.

Turkish newspaper Cumhuriyet reported that 45 people, including women and children, were taken from the Mosul consulate.

According to a Twitter feed associated with ISIL, the captives from the Turkish consulate in Mosul were taken to an undisclosed location. Two Turkish government officials told Reuters that efforts were being made to guarantee the safety of diplomatic staff.

Turkish Foreign Minister Ahmet Davutoglu said Tuesday in a tweet that all measures were being taken to ensure the safety of the consular staff.

ISIL overran Mosul, Iraq’s second-largest city, on Tuesday, driving out government forces and prompting an estimated 500,000 people to flee.

As many as half a million Iraqis fled their homes as jihadists tightened their grip beyond second city Mosul on Wednesday, and vowed an even broader offensive.

In a spectacular blow to the Shiite-led government, ISIL militants and their allies on Tuesday seized Mosul and surrounding Nineveh province as well as a string of other northern towns.

And on Wednesday ISIL declared on Twitter that it was in “complete control” of all routes in and out of Nineveh, and promised it would “not stop this series of blessed invasions”.

Members of the jihadist group also seized the Turkish consulate in Mosul and kidnapped the head of the diplomatic mission along with 24 staff, police said.

Elsewhere, they executed 15 security personnel in Kirkuk province and tried to take the oil pipeline hub of Baiji, before withdrawing when troop reinforcements arrived, officials said.

The jihadist’s surprise advance poses significant challenges to Baghdad, with a risk consultancy saying they would be bolstered by cash from Mosul’s banks, hardware from military bases and hundreds of men they freed from prison.

It also sparked a massive exodus of civilians, with families piling into cars that flooded security checkpoints outside the northern city normally home to two million people.

Prime Minister Nuri al-Maliki has responded by asking parliament to declare emergency rule and announcing citizens would be armed to fight them, while the United States warned ISIL threatened the entire region.

On Wednesday, gunmen in military uniforms and all-black clothing guarded government buildings and banks in Mosul, said witnesses reached by telephone from Bashiqa, a town to the east.

They called over loudspeakers for government employees to go back to work.

“I did not open the door of the shop since last Thursday because of the security conditions,” said Abu Ahmed, a 30-year-old shopkeeper.

‘Mosques converted to clinics’

The International Organisation for Migration said its sources in Mosul estimated the violence leading up to the jihadists’ takeover “displaced over 500,000 people in and around the city”.

The violence “has resulted in a high number of casualties among civilians,” the IOM said, adding fighting restricted access to four hospitals.

“Some mosques have been converted to clinics to treat casualties,” it said.

Witnesses reported that dozens of families were still fleeing, but Abu Ahmed said: “I will remain in Mosul. This is my city in any case, and the city is calm now.”

Bassam Mohammed, a 25-year-old student, said he too would stay.

“But I am afraid about freedoms, and I am especially afraid that they will impose new laws on us,” he said.

Known for its ruthless tactics and suicide bombers, ISIL is arguably the most capable force fighting President Bashar Assad inside Syria as well as the most powerful militant group in Iraq.

‘Entire region threatened’

The takeover of Mosul prompted the United States to voice deep concern about the “extremely serious” situation and warn that ISIL poses “a threat to the entire region”.

ISIL is led by the shadowy Abu Bakr al-Baghdadi and backed by thousands of Islamist fighters in Syria and Iraq, many of them Westerners, and it appears to be surpassing Al-Qaeda as the world’s most dangerous jihadist group.

On Wednesday, the Syrian government said it was ready to help Baghdad in its fight against “terrorism”, while the rebel Free Syrian Army called for support from Arab states for its own battle against ISIL in Syria.

The New York-based Eurasia Group consultancy said the jihadist offensive would have limited impact on Iraq’s oil exports, the majority of which are from the mainly Shiite south.

“ISIS will use cash reserves from Mosul’s banks, military equipment from seized military and police bases, and the release of 2,500 fighters from local jails to bolster its military and financial capacity,” said Ayham Kamel, its Middle East and north Africa director.

“We do not anticipate a sharp deterioration in the security environment in these more stable (southern) provinces that would materially impact Iraq’s oil export volumes,” he said.

Iraq, which boasts among the highest reserves of oil and gas in the world, produces about 3.5 million barrels of oil per day, with exports in February reaching 2.8 million bpd, the highest level in a quarter of a century.

A senior government official said “the oil sector is not affected and will not be affected by what is happening, because most of the facilities are in central and south Iraq.”

But he warned that would change if the militants were to make a new, successful assault on Baiji, a key hub on the export pipeline from the northern oil fields around Kirkuk to Turkey.