ISIL fighters have closed the streets around Mosul's Grand al-Nuri Mosque, residents said, apparently in preparation for a final showdown in the battle against Iraqi forces over their last major stronghold in the country.
Dozens of fighters were seen by residents taking up positions in the past 48 hours around the medieval mosque, the site where ISIL leader Abu Bakr al-Baghdadi declared a caliphate in July 2014.
Islamic State of Iraq and the Levant's black flag has been flying from the mosque since the fighters captured Mosul and seized swathes of Iraq and Syria in the summer of 2014.
"Daesh's fighters know that the mosque is the most important target and they are preparing for a major battle there," said Hisham al-Hashemi, who advises several Middle East governments, including Iraq's, on ISIL, using an Arabic acronym for the group.
Military sources said the move by ISIL fighters was aimed at preventing any infiltration by advancing Iraqi forces, who are closing in on the remaining pockets of territory held by the armed group.
The fall of the city would, in effect, mark the end of the Iraqi half of the self-styled caliphate. Meanwhile in Syria, Kurdish forces backed by US air raids are besieging ISIL forces in the city of Raqqa, the fighters' de facto capital in that country.
Up to 200,000 people still live in harrowing conditions behind ISIL lines in Mosul, running low on food, water and medicine.
Civilians fleeing the fighting told Al Jazeera about the terrible conditions they have been living in.
Tired and panicked, they desribed starving conditions with limited access to water
A fleeing man said that during the Muslim fasting month of Ramadan, which is currently under way, he has been surviving with flour and water.
An older woman said that they were being treated as prisoners and had no food or water.
Iraqi forces launched a major US-backed operation to retake Mosul in October last year, fighting their way to the city and retaking its eastern side before setting their sights on its smaller but more densely populated west.
The battle has taken a heavy toll on civilians, pushing hundreds of thousands to flee, while hundreds more have been killed or wounded.
|Iraqi forces help women who fled their homes during a fight in Mosul's al-Zanjili neighbourhood|