A security source in northern Iraq's Nineveh province told the Arabic-language Alsumaria News on condition of anonymity, "The leadership of the extremist group threatened to cut both ears if the escapes are repeated".
During the battle for Mosul's eastern half, the morgue worker said he had received the corpses of 72 militants in a single day, estimating a total of 2,000 had passed through in the three months it took Iraqi forces to rout them.
The country's military said jihadists fired a chlorine-filled rocket at troops who are trying to seize the west of the Iraqi city from IS.
Gen. Joseph Martin, head of ground forces for the USA -led coalition fighting Daesh, said by telephone.
A senior Isis religious leader has been killed in an airstrike in western Mosul, Iraqi government forces have claimed.
According to a report published by the Anadolu Agency on Wednesday, the strike targeted several civilian homes in a residential area of Mosul's al-Yarmouk neighborhood, which was recently liberated from Daesh.
Dorrian said ISIS is using "no single tactic" to slow Iraqi forces' progress: "They have a layered defense and they've had two years to build it".
In contrast, the number of militants has dwindled to less than 2,000, most of whom are hiding in the heavily populated neighborhoods of western Mosul.
Clashes are expected to continue in the area.
"The federal police penetrated the old city and killed 13 terrorists, and destroyed 7 booby-trapped vehicles of Daesh in the Bab al-Jadid axis towards the al-Nuri Mosque in western Mosul", police commander Maj.
QAYYARA, Iraq, April 12 (Reuters) - The stench hits you long before you reach the morgue where the latest casualties of war between Islamic State militants and Iraqi forces are kept.
The offensive is part of a wider campaign launched last October to retake the entire city, which IS overran in mid-2014.