SYRIAN government troops and foreign volunteers pushed forward on two fronts into insurgent-occupied east Aleppo yesterday.

The army expanded the foothold in the north-eastern Hanano district that it had won earlier in the week, capturing most of the area.

Other units, supported by the al-Quds Brigade of Palestinian refugees, struck deep into the Sheikh Lufti and Ard al-Hamra districts in the south-east.

They captured a key hilltop after fierce fighting.

Meanwhile, Russian military chemical weapons experts said they had found evidence that internationally banned mustard gas was used on a village north of Aleppo held by the Kurdish YPG militia.

An unexploded shell fired at Ma’arat Umm Hawsh in September contained up to 1.5 litres of an unknown black oily liquid.

“An express analysis of its content by a portable infrared spectrometer revealed the presence of a chemical warfare blister agent known as yperite, or mustard gas,” the Radiological, Chemical and Biological Defence Forces said.

The attack in September, blamed on Isis, affected more than 40 people, with some victims describing symptoms of mustard gas exposure.

On Thursday night, the Syrian air force denied claims by Turkey that it had bombed the country’s invading troops near al-Bab to the east, killing three and wounding 10.

The YPG again accused Ankara of trying to occupy northern Syria “under the pretext of fighting against terror.”

Yesterday, another Turkish soldier was killed and five were wounded by Isis terrorists.

The previous night, a US soldier was killed by an “improvised explosive device” in the border village of Ayn Issa to the north.