Iraqi forces have retaken more than a third of west Mosul from the Daesh terrorist group, a commander said, as Baghdad's troops fought to advance deeper into the city yesterday.

Iraqi forces launched the operation to recapture west Mosul -- the most populated urban area still under Daesh control -- on Feb. 19, retaking a series of areas as they advanced up from the south.

Officers have said that terrorists' resistance is weakening, but tough fighting -- including in the Old City, a warren of narrow streets and closely-spaced buildings where hundreds of thousands of civilians may still reside -- remains ahead.

"Around more than a third of the right bank [west Mosul] is under the control of our units," Staff Major General Maan al-Saadi of the elite Counter-Terrorism Service told AFP.

CTS forces were battling Daesh inside the Mosul al-Jadida and Al-Aghawat areas in west Mosul yesterday, said Saadi, adding that he expected the fighting there to be completed in the coming hours. Iraq's Joint Operations Command (JOC) said that forces from the Rapid Response Division, another special forces unit, and the federal police were attacking the Bab al-Toub area on the edge of the Old City. But the process of advancing in Mosul is laborious, Saadi said. The city, Iraq's second biggest, is the largest urban center captured by Daesh in both countries and its de facto capital in Iraq. Raqqa is its capital in Syria. Daesh was thought to have up to 6,000 militants in Mosul when the government's offensive started in mid-October.