Iraqi security forces have been pushed out of the capital by IS militants.

Ramadi city, the capital of Iraq’s Sunni dominated Western Anbar province has had full control taken over by Islamic State militants according to the Islamic State adding that it had seized tanks and killed “dozens of apostates” (Iraqi security forces).

Prime Minister Haider al-Abadi has deployed Shi’ite militia to take back the city; a move earlier held back due to the fear of provoking a sectarian backlash. The fall of the city is said to be the biggest victory for the Islamic State in Iraq since last year’s push back of the militant group by security forces, Shi’ite militia and US-led coalition air strikes.

The US Defence Department refused to confirm the capture of the city and played down the impact on the Iraqi military campaign.

“Ramadi has been contested since last summer and ISIL, now has the advantage,” said Pentagon spokeswoman Elissa Smith. While acknowledging that it is a “propaganda boost” for IS, Smith said that the capture of the city would not signify IS’s dominance over the broad Iraqi military campaign,

“That just means the coalition will have to support Iraqi forces to take it back later.”

“Most of the troops withdrew from the operations command headquarters and Daesh(IS) fighters managed to break in from the southern gate,” said an officer who withdrew.

Earlier on Sunday, Prime Minister Haider al-Abadi ordered troops to stand their ground saying that he was deploying Shia militia to the city.

Government troops were running out of ammunition to thwart the IS advance. Anbar provincial council member Athal Fahdawi called the situation in Ramadi a “total collapse”.

The US said on Saturday that a senior Islamic State figure had been killed in a raid by its special forces. It had also been carrying out its highest number of air strikes in a single location near Ramadi during a span of 24 hours up until Saturday morning.