Islamic State militants raised their black flag over the local government compound in the Iraqi city of Ramadi yesterday and claimed victory through mosque loudspeakers after overrunning most of the western provincial capital.

The insurgents attacked Ramadi overnight using six suicide car bombs to reach the city centre, where the Anbar governorate compound is located, police sources said.

Fighting continued yesterday in parts of Ramadi, 100 kilometres west of Baghdad, and government forces were still in control of a military command centre to the west of the city – the capital of Iraq’s largest province.

If Ramadi were to fall completely to Islamic State it would be a strategic blow to Prime Minister Haider al-Abadi’s government, only six weeks after the army and Shi’ite militias took the city of Tikrit from Islamic State.

“The situation in Ramadi is dire, but the city has not fallen and the battle against criminal Daesh is still ongoing,” Anbar governor Sohaib al-Rawi said on Twitter.

A massacre will take place and all of us will be slaughtered

Ramadi has been contested since last year but the insurgents renewed their offensive in April, sending more than 130,000 people fleeing. An army major whose regiment is positioned near Anbar operations command described the situation as critical and said the militants had taken control of the only major supply route into the city, making it difficult to send reinforcements. Most army and police units have retreated to the area around the operation command to protect it, but some elite counter-terrorism forces are “fighting for their lives” in the Malaab district of central Ramadi, where they are surrounded.

“If the government does not send any reinforcements and the coalition air force does not rescue us, I can confirm we will lose all Ramadi by midnight,” the major said.

“A massacre will take place and all of us will be slaughtered. We have been defending the city for months and we don’t deserve to end like this. It’s humiliating.”

Sunni families fleeing the violence in Ramadi, Iraq, yesterday as Islamic State militants raised their black flag over the local government compound after overrunning most of the western provincial capital.

Ramadi is one of a small handful of towns in Anbar to have remained under government control. The rest of the vast desert province bordering Saudi Arabia, Syria and Jordan, is held by Islamic State.

The militant group said it had stormed Ramadi’s provincial government compound and taken control after “eliminating the apostates” who remained inside.

The offensive began in the early hours yesterday, with the militants using an armoured bulldozer to remove blast walls blocking the road to the police department ad­jacent to the governorate building and blew the vehicle up when it reached there. A Humvee packed with explosives targeted the education department in the same compound, and a third car bomb was detonated at the western entrance to the governorate building itself.

Three more car bombs blew up near the Anbar Operations Command.