#MosulOps: Troops advance amid fears IS 'stockpiling chemical weapons'

Iraqi forces have regrouped and are planning a fresh push into Mosul from the southern and eastern edges of the city, amid fears that fiercely resistant Islamic State fighters are stockpiling chemical weapons.

Government troops are preparing to advance toward Mosul airport on the city's southern edge to increase pressure on militants currently facing street battles with elite forces who have breached the city's eastern defences.

Meanwhile, IS fighters are asserting their control of the city, deploying young boys wearing explosives belts into alleyways and stockpiling ammonia and sulphur, the UN has warned.

"We need to put wider pressure on the enemy in different areas," said Major-General Thamer al-Husseini, commander of the elite police unit.

"Our forces have begun the attack on Arbajiyah. The clashes are ongoing," Staff Lieutenant Colonel Muntadhar Salem said, referring to an eastern area of the city, where the first row of buildings have been seized.

"We are within firing range of Karkukli but the full attack has not yet started," he said, referring to another eastern neighbourhood.

The latest fighting came "after a few days of quiet," he said.

The IS-held city is surrounded by 100,000 coalition fighters, three weeks since the launch of the offensive.

While elite Iraqi troops battle IS in the streets of Mosul, the rapid response forces, which took the town of Hammam al-Alil on Monday, will resume their advance north, officers told Reuters.

However, Iraqi troops have faced stronger than expected resistance from IS fighters.

The UN human rights office said on Friday militants had executed scores more people around Mosul this week and are reportedly readying ammonia and sulphur in civilian areas, possibly for use as chemical weapons, spokeswoman Ravina Shamdasani.

A mass grave with more than 100 bodies found in Hammam al-Alil was one of several IS killing grounds, Shamdasani said, citing information from a man who played dead during a mass execution.

Public executions were being carried out for "treason and collaboration" with Iraqi forces trying to recapture the city, or for the use of banned mobile phones or desertion.

People with explosive belts, possibly teenagers or young boys, were being deployed in the alleys of Old Mosul, while abducted women were being "distributed" to fighters or told they would be used to accompany IS convoys, she said.