Iraqi forces have seized full control of Mosul University in their battle with so-called Islamic State, Iraqi state television says.
Military forces have been attempting to retake the city - the last major IS stronghold in Iraq - since October.
Iraqi officials said the IS group had used laboratories in the university complex to make chemical weapons.
The head of the country's counter-terrorism operations said retaking the area was a significant victory.
"This great scientific and cultural building was liberated by the heroes," Lt Gen Talib Shaghati, said. "The liberation of the University of Mosul means much, given its cultural, social and human symbolism."
Elite troops had entered the compound on Friday as part of a major push into new territory.
Airstrike kills dozens
Meanwhile, up to 30 civilians have died in an air strike on a Mosul district still held by Islamic State.
Locals said they saw at least three missiles hit the western Mosul al-Jadida area on Thursday, in a raid that appeared to target the house of a senior jihadist, Harbi Abdel Qader.
He was not in the building at the time, but a local says several members of his family were among the dead.
Reuters could not verify the accounts independently.
The witnesses said it was not immediately clear if the attack was carried out by the U.S.-led coalition fighting Islamic State, or by Iraqi forces that have been making advances against the jihadists in the city.
Iraqi military officials claim they now control a large majority of the city's eastern half.
They also control three of the five key bridges crossing the river Tigris, which divides Mosul in two.
The bridges were targeted by coalition air strikes in October with the aim of limiting the ability of IS to resupply or reinforce their positions in the east.
The campaign began in October, but got off to a slow start in the face of tough IS defence and counter-attacks.
But significant gains along the river may open up western Mosul, which is still under IS control, to Iraqi forces seeking to advance.