Harrowing pictures have emerged showing a second obese executioner beheading a man for 'mocking Islam' in front of children in the ISIS' stronghold of Raqqa.

The horrifying images emerged at the same time as the increasingly-besieged terror group shared pictures of its 'softer side' - showing militants handing out advice on giving to charity during Ramadan.

And it is not the only vile 'execution' to happen in recent days: another series shows a man's head sawn off with a knife. His supposed crime was 'pledging allegiance to the infidels'.

Vile: This man was accused of 'mocking Islam', according to ISIS, who circulated these pictures of his murder in front of a large crowd men and boys in the extremists' stronghold of Raqqa, in Syria

Horrific: The murderer looks like the obese killer dubbed 'The Bulldozer', who was captured last month

Obese executioner: The 30-stone jihadIi (pictured above) became infamous as one of ISIS's most feared executioners - until he was caught, topless, by the Syrian army

The pictures from the Raqqa murder shows a man sitting on a chair in a town square, surrounded by a crowd of men and boys, some who appear to be little older than seven or eight.

The bespectacled executioner - who bares more than a passing resemblance to The Bulldozer, the obese killer captured by the Syrian army last month - is seen wielding the massive weapon, apparently taking off the man's head in one sweep.

In one picture, members of the crowd seem to be smiling as the medieval punishment is carried out.

The pictures appear to have been circulated as the extremist group struggles to hold onto Manbij, currently encircled by the Syrian Democratic Forces, a Kurdish-dominated group aided by U.S. special forces that also includes Arab fighters.

ISIS have already been driven out of Fallujah, which had been their biggest base in Iraq.

Should it lose Manbij, it will lose one of its most crucial supply routes to Raqqa - dealing the evil extremists a double blow.

Barbaric: This man was accused of 'pledging allegiance to the infidels' - and had his head sawn off with a small knife by a man who hid behind a mask to protect his identity

Image control: However, the group also shared pictures of it advising people on charitable giving during the holy month of Ramadan, which comes to an end this week

Hypocrites: Their call for people to be charitable is at odds with their violent actions. In the last week, the group has claimed responsibility for the deaths of at least 162 people in Baghdad and Bangladesh

As ISIS comes under increasing pressure, so it has apparently increased its suicide attacks.

At least 142 people are now thought to have lost their lives in the Baghdad bombing on Sunday, while 20 people were murdered in Bangladesh by men swearing allegiance to ISIS.