In a statement released early on Monday, the terror group said it had seized tanks and killed "dozens of apostates" - the term used by IS to describe members of the Iraqi security forces.

Contrary to IS' assertion of full control of Ramadi, however, the Pentagon said it was continuing to monitor reports of continued "tough fighting" there.

"It is too early to make definitive statements about the situation on the ground there at this time," said Defense Department spokeswoman Maureen Schumann.

Suicide attacks

Iraqi forces were reported on Sunday to have retreated from Ramadi after IS launched a string of suicide bomb attacks which began on Friday. At least 15 police officers were killed in the violence on Sunday alone.

According to the International Organization for Migration (IOM), the recent onslaught by the IS has forced approximately 8,000 to flee the area.

Many of Ramadi's citizens were reportedly prevented from leaving their homes by militants of the terror group.

"We are extremely concerned about massacres that could be committed in the next hours," said spokesmen and adviser to the provincial governor, Muhanned Haimour.

Also on Sunday, however, Syrian regime forces succeeded in driving IS fighters out of the Syrian city of Palmyra, which the militants had temporarily seized on Saturday.

ksb/rc (Reuters, AFP, AP)