Islamic State militants have begun torching their archives in their besieged bastion of Mosul's Old City, where Iraqi forces have launched a major offensive to route the jihadists by 10 June, Al-Arabiya news channel reported on Tuesday.
"The militants began to burn large quantities of the archives including those of its al-Hessbah (IS's religious police), security and recruitment offices and treasury," Al-Arabiya cited a security source as saying.
The burning of the archives is a "clear indication" of a major collapse within IS's ranks and is aimed at concealing its crimes against civilians and the identities of its accomplices, the source said
"IS’s burning of its archives is to prevent the detection of its crimes against civilians, and an attempt to conceal the identity of its supporters who backed its militants in committing crimes against innocent people,” said the source.
The archives were set alight in IS headquarters close to residential areas, after the evacuation of its fighters, the source said.
The few hundred IS militants holed up in the dense Old City are experiencing heavy defeats daily due to many of their commanders in Mosul having been killed in battle or escaped before the push to re-capture the group's final holdouts there began on Sunday, according to the source.
"The battle for the liberation of old Mosul will end very soon," the source stated.
Also on Tuesday, the Iraqi police took over a commando training centre in Zanjili, one of the three districts adjacent to Mosul's Old City still under IS control, the IraqiNews.com website reported.
Clashes have intensified in recent days between the US-backed Iraqi forces and IS militants in an around the Old City, where an estimated 200,000 civilians are trapped.
IS overran Mosul, 400 km north of Baghdad, in July 2014 during a lightening campaign when it captured swathes of territory in Iraq and Syria and established a so-called 'Islamic Caliphate' there with Mosul as its capital.