Iraqi security forces entered the University of Anbar in the western city of Ramadi on Sunday and clashed with Islamic State (Isis) militants inside the compound, the joint operations command said in a statement.
Capture of the sprawling complex, which a spokesman said had been used as an insurgent command base, could advance government efforts to retake Ramadi, the capital of Anbar, Iraq's largest province, after its fall to Isis in May.
Security forces and militia groups have launched an offensive in the Sunni heartland, but progress has been incremental.
"We announce to you the entry of the counter-terrorism forces into the University of Anbar. They are now engaging in battles to clean it up from the remains of Daesh [Isis] and dismantling bombs and clearing roads," the statement broadcast on state television said, using another name for Islamic State.
Security forces advancing toward the nearby district of al-Tamim had encountered Isis positions enforced by bombs and razor wires, the statement added.
A spokesman for Iraq's counter-terrorism forces, which were taking a lead role in the battle, told Reuters the troops had managed to recapture most of the university buildings after launching a surprise offensive with support from U.S.-led coalition air strikes.
"The university represents a significant stronghold and a key command base used by top Daesh commanders to orchestrate all battles in other parts of Ramadi," said Sabah al-Noamani.
He said government forces were seeking to separate the university from nearby districts to cut supply routes to retreating militants.
Anbar provincial council member Falih al-Essawi said special forces, army and federal police had managed to enter the university compound in southern Ramadi early on Sunday and were now "in full control" of the complex.
"They seized the opportunity of retreating Daesh [Isis] fighters to make more advances toward al-Tamim district in southern Ramadi," Essawi told Reuters.
He said no members of the Hashid Shaabi, the Iran-backed Shi'ite paramilitary groups which Washington has refused to coordinate with, had participated in the university operation.
U.S.-led coalition warplanes have been carrying out strikes in Iraq and neighboring Syria since August 2014 in an attempt to roll back Islamic State gains.
