Shiite militias converged on Ramadi Monday in a bid to recapture it from ISIS terrorist who dealt the Iraqi government a stinging blow by overrunning the city in a deadly three-day blitz.

Badr organization chief Hadi al-Ameri said the province's leaders should have taken up his offer of help sooner.

Various Hashed al-Shaabi units announced they had units already in Anbar -- including around the cities of Fallujah and Habbaniyah -- ready to close in on Ramadi.

A spokesman for Ketaeb Hezbollah, one of the leading Shiite paramilitary groups, said his organisation had units ready to join the Ramadi front from three directions.

"Tomorrow, God willing, these reinforcements will continue towards Anbar and Ramadi and the start of operations to cleanse the areas recently captured by Daesh will be announced," Jaafar al-Husseini told AFP.

The Terrorists used several waves of suicide car bombs to thrust into government-controlled neighborhoods on Thursday and Friday.

Anbar officials said at least 500 people died in three days.

Muhannad Haimour, spokesman and adviser to the Anbar governor, said fighting was continuing in some pockets of the city.

Iraqi military officials said all main security bases had been abandoned.

'We do not have an accurate count yet,' said the spokesman, Muhannad Haimour.

'We estimate that 500 people have been killed, both civilians and military, and approximately 8,000 have fled the city.'

The estimates are for the past three days, since Friday, when the battle for the city reached its final stages.

The 8,000 figure is in addition to the enormous exodus in April, Haimour said, when the U.N. said as many as 114,000 residents fled from Ramadi and surrounding villages at the height of the violence.

Local officials have said that ISIS carried out mass killings of Iraqi security forces and civilians.