MOSUL, Iraq (Reuters) - Iraqi special forces made further advances against Islamic State in Mosul on Monday, pushing militants from another eastern district and edging closer to army units nearby, officers in the city said.

The Counter Terrorism Service (CTS) said it was working to seize areas overlooking Mosul University in the city’s northeast, after taking over a nearby district.

The ground troops and a U.S.-led coalition backing them launched rockets and air strikes against the militants, who responded with mortars and sniper fire. Residents trickled out of the conflict zone but many also returned to their homes in areas retaken from Islamic State in recent days.

The latest advances brought more of eastern Mosul under Iraqi forces’ control a day after elite units reached the Tigris river, as the U.S.-backed offensive to drive Islamic State from its last major stronghold in the country pressed ahead with renewed vigor.

Reaching the river, which runs through the center of the northern city where up to 1.5 million people are still thought to be living, will allow Iraqi forces to begin assaults on western districts still under Islamic State’s full control.

The jihadists have fought back fiercely with suicide car bombs and snipers. Using a network of tunnels and operating close to Mosul’s civilian population, they slowed Iraqi advances in November and December.

They have also killed dozens of Iraqis in attacks in Baghdad and other cities as it comes under increased pressure.

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“The Baladiyat neighborhood is done (recaptured) and Sukkar should be done before nightfall,” Major-General Sami al-Aradi of the CTS told a Reuters reporter in Mosul.

“This area is very important because it overlooks the university (which) is a central district ... If it falls we will control the forests, the presidential palaces and the eastern bank of the Tigris,” he said.

Askari said Islamic State has used the university’s laboratories to make biological weapons and store chemicals.

The United Nations has said insurgents seized nuclear materials used for scientific research at the facility when they overran a third of Iraq in 2014.

Though the materials were not thought to be weapons grade, Islamic State has repeatedly launched rockets containing mustard agents at Iraqi and Kurdish forces.

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JOINING FLANKS

The CTS were also close to linking up nearby with the army, which has slowly encroached from the city’s northern outskirts, a commander in a regular army unit said.

“They will soon liberate other areas and hopefully finish the eastern side ... God willing, we will soon announce the liberation of the entire eastern side from Daesh (Islamic State),” Major-General Najm al-Jubbouri told another Reuters reporter in the al-Hadba apartments complex on the city’s northern edge.

Soldiers posed for photos with black Islamic State flags, and the corpses of several Islamic State fighters could be seen.

There were signs that fierce fighting still raged in parts of the complex, however. Islamic State fighters had carried out four to five suicide car bomb attacks in the area since Friday, several officers said.

Monday’s advances also consolidated Iraqi forces’ control of several districts close to the ruins of the ancient Assyrian city of Nineveh, east of the river.

CTS forces reached the east bank of the Tigris in an area further south on Sunday, an advance which will eventually enable them to begin assaults on the city’s west.

The offensive against the group, which began in October, stalled last month but has regained momentum in the last week.

Recapturing Mosul after more than two years of Islamic State rule would probably spell the end of the Iraqi wing of the group’s self-declared caliphate, which spans areas of Iraq and Syria.