Iraqi army cuts off last 'Islamic State' supply line to west Mosul

Ancient artifacts are seen inside a tunnel under the rubble of the destroyed Mosque of The Prophet Younis or Jonah in Mosul Iraq Saturday

At least 23 people were killed Sunday in deadly clashes between Iraqi forces and Daesh militants in western Mosul amid an ongoing offensive to dislodge the terrorist group from the northern city, according to a local police officer, Anadolu reported.

Federal police and Rapid Response units said they had entered the Bab al-Tob area of the Old City, where the fight is expected to be toughest due to narrow alleyways through which armored vehicles can not pass.

Inside the city troops battled the ultra-hardline Sunni Muslim terrorists, who hid among the remaining civilian population and deployed snipers and suicide vehicle bombs to defend their last major Iraq stronghold.

CTS troops stormed the al-Jadida and al-Aghawat districts on Sunday, Major General Maan al-Saadi told reporters in Mosul, saying the militants were showing signs of weakness despite initial "fierce" resistance.

A mass grave was discovered over the weekend containing the remains of hundreds of "civilian prisoners" who were executed by ISIS gangs.

"The latest statistics of the Iraqi ministry of migration shows 99,852 displaced people since the launch of operations to free the neighbourhoods of Mosul's right bank (western side)", Xinhua quoted a statement by Jassim Mohammed al-Jaf, minister of migration and displaced.

The road links Mosul to Tal Afar, another Islamic State stronghold 40 miles to the west, and then to the Syrian border.

Iraq's United Nations envoy said Friday there was no evidence that the Islamic State group had used chemical weapons in the battle for Mosul.

The army was forced to retreat earlier this week after trying to take the government buildings with too few men, so repeating a mistake that caused the deaths of up to 100 troops at the al-Salam hospital, on the eastern side of the city, in December.

The offensive to retake Mosul began October 17, led by Iraqi security forces and aided by the Kurdish Peshmerga, a Shiite-led militia, and the USA -led global coalition.

In recent months, the radical group has suffered military setbacks and lost territory in Iraq and Syria.

As many as 600,000 civilians are trapped with the militants inside the city which Iraqi forces have effectively sealed off from the rest of the territory ISIS controls in Syria and Iraq.

ISIS overran Mosul in the summer of 2014 and swept across large swaths of the country's north and west.

In Syria, it still holds Raqqa city as its main stronghold, as well as most of Deir al-Zor province, but is losing ground to an array of separate enemies, including USA -backed forces and the Russian-backed Syrian army. Iraqi forces include army, special forces, Kurdish Peshmerga, and Shia militias.