Iraqi forces and militias took up positions on the southern outskirts of Ramadi, officials said Wednesday, taking two neighbourhoods and moving into Anbar university.

Army and police forces as well as allied paramilitaries clashed with fighters from the Islamic State group to take full control of Taesh and Humeyrah, an army colonel said.

"Daesh was forced to flee after the clashes," the officer said, using an Arabic acronym for IS.

"Iraqi security and Hashed forces took control of both neighbourhoods. They also managed to enter the university but have yet to liberate it," he said.

Humeyrah, Taesh and the university are outside the main road circling the city from the south.

Thousands of federal forces and Hashed al-Shaabi ("popular mobilisation" in Arabic) -- an umbrella for mostly Shiite militias and volunteers -- are closing in on Ramadi.

IS fighters seized the capital of the western province of Anbar -- Iraq's largest -- on May 17 after a three-day blitz that prompted a chaotic of the security forces.

Raja al-Issawi, a provincial council member, confirmed the two neighbourhoods on the southern outskirts of the city had been retaken, describing their capture as "important to cut Daesh supplies".

Thousands of Iraqi forces are positioned a few kilometres east of Ramadi and others are clearing areas north of the city.