After weeks in near-deadlock, Iraqi troops pushed further into the southeastern neighborhoods of Mosul, one of the final strongholds of the so-called "Islamic State,"  officers said.

Just after 6am Iraqi air support and the US-led coalition began hitting the residential neighborhood of al-Salam with a series of heavy airstrikes, kicking off the assault.

The army's Ninth Armored Division surged hundreds of meters ahead and by evening Lieutenant General Abdul-Amir Yarellah pronounced a key hospital retaken.

"The hospital was a Daesh (IS) base," said Lieutenant Ahmed Abu Fadl. "They were treating their wounded there." He hoped retaking Salam Hospital would diminish IS's ability to launch counterattacks in the area.

The IS news agency appeared to confirm the division's statements, saying three car bombers struck the troops near Salam hospital.

Residents of IS-controlled areas in eastern Mosul said by telephone the Iraqi army were getting close to the Tigris River.

"The fighting right now is very heavy - Iraqi forces have gone past our neighborhood without entering it. Our area is now practically surrounded by the river and the Iraqi forces," said a resident of the Palestine neighborhood.

Slow progress

For more than a month the Ninth Armored Division had been making slow progress, caught up in close-quarter combat with IS on the southeastern fringes of the city.

The elite Counter-Terrorism Service controlled 23 neighborhoods in east Mosul and the ninth division controlled six, said Yahya Rasool, spokesman for the Joint Operations Command that heads the assault.

He said the southern front had stopped its advance north within striking distance of Mosul airport, and the northern front had also made slow progress in recent days.   

A colonel in the armored division said they ultimately aimed to reach Mosul's Fourth Bridge, the southernmost of five bridges that span the Tigris, all of which have been hit by air-strikes to prevent IS sending reinforcements and suicide car bombs.

"We are using a new tactic - increasing the numbers of advancing forces and also attacking from multiple fronts to take the initiative and prevent Daesh fighters from organizing any counter-attacks," the colonel said by telephone.

He said the sprawling neighborhood of Wahda could serve as a launchpad to advance on the Fourth Bridge.

New IS spokesman Abu al-Hassan al-Muhajir urged fighters in Mosul and in the Syrian city of Raqqa to keep fighting and not retreat, in a 30-minute recording distributed online. 

About 82,000 people had been displaced by the Mosul operation which began seven weeks ago, according to the United Nations.

aw/bw (AFP, Reuters, AP)