Hundreds of ISIS militants were reportedly killed during Friday's advance, which came as Iraqi counterterrorism forces also announced that troops had made it Mosul's Second Bridge on the river's east bank
Counterterror forces this week reached the east bank of the Tigris for the first time since the large-scale military operation to reclaim Mosul began in October. ISIS seized control of the city, now its last major stronghold in Iraq, in 2014.
The latest phase in the bid to retake Mosul has advanced more quickly than expected, partly because thousands of Iraqi federal police joined coalition troops that included the Iraqi army, counterterror forces, Kurdish Peshmerga fighters and Shiite-led paramilitaries.
The new government complex in eastern Mosul as well as several Mosul University buildings had at one time been a headquarters and killing ground for ISIS fighters.
Iraqi forces discovered large amounts of suspected chemical substances and "a bomb factory" at the university, a strategic base for militants, according to Sabah al Numan, spokesman for Iraqi counterterrorism forces. The materials were being tested.
Additionally, Iraqi federal police announced Saturday that intelligence information had led them to a factory used to produce chemical and toxic material in explosives. They discovered the facility Friday night in al-Bir, about 45 kilometers (27 miles) south of Mosul.
ISIS militants have used chemical weapons such as mustard gas
in the past, according Iraqi and US officials.
By Friday, ISIS had destroyed all five bridges crossing the Tigris River in Mosul, an attempt to slow the advance of Iraqi troops toward the city's western side, according to Lt. Gen. Abdul Amir Rasheed Yarallah, commander of Iraqi forces in Nineveh province.
The Tigris divides the eastern and western parts of the city; Iraqi-led forces have not crossed into or started any operations in western Mosul.
The bridges had already been damaged in airstrikes by the US-led coalition in recent weeks. In previous instances where ISIS took out bridges, Iraqi forces built temporary or floating structures, slowing down troops but not deterring their advance.
Saadi of the counterterrorism forces told CNN this week that night raids have been effective against ISIS headquarters and stretches of eastern Mosul.
US Air Force Col. John L. Dorrian, spokesman for the US-led operation against ISIS, said in a video conference Tuesday that Iraqi forces were making progress with the assistance of coalition airstrikes.