Fighters from the Islamic State of Iraq and the Levant (ISIL) have reportedly taken control of the western Iraqi city of Ramadi over the weekend after killing dozens of Iraqi Security Forces.

The intense fighting, coupled with multiple suicide car-bomb attacks, reportedly prompted the Iraqi military and police personnel to abandon the capital of Anbar province, and retreat to an area east of the city.

In a statement, ISIL claimed to have seized the 8th Brigade Army Base, along with tanks and missile launchers left behind by the fleeing soldiers.

An undisclosed Iraqi Army official said the government forces failed to counter the ISIL offensive due to lack of ammunition, and that the majority of them had retreated to a military base in the city of Khalidiya, east of Ramadi.

A source in the Anbar governor’s office confirmed to the BBC that the militants currently control the city, and all government forces had pulled out.

In addition, images posted on social media sites showed military vehicles speeding out of Ramadi, with soldiers gripping onto their sides.

"Ramadi has been contested since last summer and ISIL now has the advantage."

Iraqi Prime Minister Haider al-Abadi had called on security forces to hold their positions across the Anbar province, so as to prevent militants from further advancing into the city.

Haider al-Abadi said: "There is continuous air cover that will help ground troops there hold their positions while waiting for support from other forces and the Popular Mobilisation Units."

The US has downplayed the fall saying the loss would not put ISIL on top in the ongoing Iraq military campaign.

Pentagon spokeswoman Elissa Smith said: "Ramadi has been contested since last summer and ISIL now has the advantage.

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

The move, which reportedly killed more than 500 people including both soldiers and civilians, comes a day after a US Special-Operations team killed a senior ISIL leader in Syria, who managed the group’s illicit oil, gas, and financial operations.

US Defence Secretary Ash Carter said: "Last night, at the direction of the Commander in Chief, I ordered US special operations forces to conduct an operation in al-Amr in eastern Syria to capture an ISIL senior leader known as Abu Sayyaf and his wife Umm Sayyaf."