(Adds forces find chemical substances)
MOSUL, Iraq, Jan 14 (Reuters) - Iraqi special forces battled Islamic State militants inside the Mosul University campus on Saturday in a second day of fierce clashes in the complex and also discovered chemicals used to try to make weapons, officers said.
"There are still clashes. We entered the university and cleared the technical institute, dentistry and antiquities departments," Lieutenant General Abdelwahab al-Saadi of the Counter Terrorism Service (CTS) told a Reuters reporter in the complex.
"In the coming hours it will be liberated completely," he said.
CTS troops had gathered in the university canteen. As they unfurled a map of the area, a suspected Islamic State drone flew overhead and they shot at it.
The Iraqi forces also found chemical substances IS had used to try to make weapons, CTS commander Sami al-Aridhi said.
The United Nations says the militants seized nuclear materials used for scientific research from the university when they overran Mosul and vast areas of northern Iraq and eastern Syria in 2014.
Islamic State have used chemical agents including mustard gas in a number of attacks in Iraq and Syria, U.S. officials, rights groups and residents have said.
Recapturing the university would be a crucial strategic gain and allow Iraqi forces to advance quicker towards the Tigris river, from where they will be able to launch attacks on the city's west, still all under IS control, military officers say. (Reporting by Isabel Coles, writing by John Davison, Editing by Angus MacSwan)