Iraqis, displaced from Mosul, receive aid rations at the Hammam al-Alil camp for the internally displaced, south of Mosul, on March 16, 2017.

A commander said Friday that Iraqi forces have gained ground from jihadists inside the Old City of Mosul, an area that could see some of the toughest fighting of the battle for the northern metropolis.

Iraqi forces launched an operation on February 19 to retake the west side of Mosul – the most populous area still held by ISIS – and have retaken several neighborhoods. But the pace of their advance has periodically slowed because of bad weather that has hampered air support.

The Old City, where hundreds of thousands of civilians are believed to have stayed on under IS rule, is a warren of narrow streets that restricts the use of large armored vehicles.

“Federal police and Rapid Response units imposed their complete control over the Al-Basha Mosque… and the Bab al-Saray market in the Old City,” federal police Lieutenant General Raed Shakir Jawdat, the commander of the federal police, said in a statement.

Iraqi forces launched the operation to recapture Mosul — the jihadists’ last major urban bastion in the country — in October, retaking its east side before setting their sites on the smaller but more densely populated west.