Dozens of civilians attempting to flee the besieged Iraqi city of Mosul have been murdered and their bodies hung from electricity poles by Isis, according to reports.

More than 300,000 people have attempted to flee the city in the north of the country - once the largest controlled by Isis - with reports of the jihadists using civilians as human shields as they lose territory.

Since the start of the campaign in October fierce fighting has seen the east of the city retaken from the extremists with pockets of resistance remaining to the west of the River Tigris.

But as Iraqi forces – backed by Western airstrikes – advance, witnesses say Isis militants have hung the bodies of civilians from electricity poles. The civilians were murdered as punishment for trying to escape, say reports.

One witness said he had found the mutilated body of a relative strung up from an electricity pole in the Tenek district.

He added that the body was found alongside three other young men caught trying to flee the city, which was taken by an Isis lightning advance in 2014.

"Their appearance was shocking. We weren't able to get them down and they have been there for two days," said the relative.

In a series of tweets about the incident the Kurdistan Region Security Council put the number of executed civilians as high as 140.

It was also reported by Reuters that in the Old City district more than 40 civilians were killed trying to escape, according to a resident of the Farouq district.

Another resident said a family of six, including an elderly woman, had also been killed for the same reason.

5 April 2017: Iraqis stand near a heavily damaged house in the Mosul al-Jadida neighbourhood in the western part of the northern city of Mosul Ahmad al-Rubaye/AFP

Earlier this week the UN reported that at least 307 civilians were killed and 273 wounded in western Mosul in five weeks over February and March.

It has been widely reported that the jihadists have herded people into booby-trapped buildings to serve as human shields and have shot at those who flee.

Human rights organisations say that more than 30,000 escapees are housed in the Hamam al-Alil refugee camp to the south of the city.

Mosul Hamam al-Alil refugee camp Carl Court
Hamam al-Alil refugee camp on the outskirts of Mosul Carl Court/Getty Images