Iraqi troops continue to battle ISIS in Mosul amidst reports of civilian executions

Elite Iraqi troops battled ISIS in the streets of Mosul on Friday, as the UN reported jihadists had executed dozens of people inside the city for alleged "treason."

With ISIS also on the defensive in neighboring Syria, US-backed forces pressed an advance on jihadist bastion Raqa after a sandstorm eased.

The high winds in the desert that separates the Syrian Kurdish-Arab militia alliance from the jihadists' stronghold in the Euphrates Valley had slowed their advance on Thursday as visibility levels plummeted.

Iraqi forces too had regrouped after meeting stronger than expected resistance from ISIS fighters on the east bank of the Tigris River, which runs through Mosul, after thrusting into the built-up area last week.

Commanders of Iraq's elite Counter-Terrorism Service (CTS) said that troops were advancing on two eastern neighborhoods of the city.

In a house near the front line, Staff Lt. Col. Muntadhar Salem clutched a radio in one hand and a tablet in the other with a map showing several rows of buildings recaptured by CTS.

As the troops waited for orders to push forward, incoming mortar rounds shook the pink curtains on the windows of the house.

Inside Mosul itself, ISIS fighters reportedly shot dead more than 60 people this week and hung some of their bodies from poles after claiming they had collaborated with Iraqi troops, the UN human rights office said Friday.

"On Tuesday, ISIS reportedly shot and killed 40 civilians in Mosul city after accusing them of 'treason and collaboration'" with the ISF, rights office spokeswoman Ravina Shamdasani said in a statement released in Geneva.

And on Wednesday, ISIS slaughtered another 20 people at the Ghabat Military Base in northern Mosul after accusing them of "leaking information," the UN statement said. 

The battle to retake Mosul is now in its fourth week, and while troops have entered the built-up area, there are weeks, if not months, of fighting still to go.

"Our forces have begun the attack on Arbajiyah. The clashes are ongoing," Salem said, referring to an area in the east of the city.

'Within firing range'

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

Another CTS officer, Lt. Col. Ali Hussein Fadhel, said the first row of buildings in Arbajiyah had been seized.

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

Iraqi forces launched the operation to retake Mosul on October 17, with federal and Kurdish regional forces closing in on the city from three sides.

Pro-government Shiite paramilitaries later began an advance on the town of Tal Afar, which commands the city's western approaches, with the goal of cutting the jihadists off from territory they control in neighbouring Syria.

The advance up the Tigris Valley from the south has been slowest. The troops on that front had the farthest to cover, with a string of jihadist-held towns in their path.

On Thursday, the battle neared the remains of ancient Nimrud, some 20 miles south of Mosul, raising fears for the famed heritage site already ravaged by jihadist bombs and sledgehammers.

Syrian forces converging near Raqa

In Syria, the US-backed Syrian Democratic Forces (SDF) said their advance on Raqa was back on track after a sandstorm that swept through the area on Thursday.

"We seized control of two new villages yesterday but we didn't advance as far as planned because of the sandstorm," SDF commander Merkhas Kamishlo told AFP.

Fighting has focused on the ISIS-held village of Al-Heisha, around 40 kilometres (25 miles) north of Raqa.

An AFP correspondent reported heavy air strikes on Friday morning by the US-led coalition supporting the SDF forces. 

"Al-Heisha is totally besieged and overnight the US-led coalition hit four Daesh positions inside the village, and destroyed a vehicle being prepared for use as a bomb," Kamishlo said, using an Arabic acronym for ISIS. 

The SDF launched its offensive last weekend and has been pushing south from areas near the Turkish border towards Raqa.

Kamishlo said SDF forces advancing south from the towns of Ain Issa and Suluk were close to converging at a position some 30 kilometres (20 miles) from Raqa.

The military in Russia, which has sided with the Damascus regime, said Friday it had evidence of the use of chemical weapons by rebels in Syria's besieged eastern city of Aleppo, a charge denied by the opposition.

"Experts from the Russian defense ministry have found unexploded artillery ammunition belonging to terrorists which contain toxic substances," the military said in a statement.