Aleppo is today under siege as remaining rebels clash with government and Russian forces in the eastern part of the city.

Witnessing the catastrophic scenes around them are ordinary Syrians – men, women, and children who are trapped and increasingly desperate as their options run out.

Some of those seemingly caught up in the violence have been posting chilling words online, sharing ‘final’ messages with a world they feel has abandoned them.

While the authenticity of the posts cannot be verified independently – the sentiment is nevertheless harrowing. Indeed, as one commentator on Twitter stated: "I don't know if the account is real or not but the suffering of the civilians of Aleppo is real."

And international humanitarian groups are already describing recent events as a “complete meltdown of humanity”.

As the bloody four-year long battle comes to an end, Russian state media is reporting that the rebels are cornered into an area of less than 5sq km.

The UN says that some 80 people have been executed by pro-government fighters in their homes and on the streets – adding that at least 13 of the dead are children.

"In these hours, it looks like a complete meltdown of humanity in Aleppo," the UN’s Rupert Colville commented today.

Citing a doctor on the ground, Unicef has also said that around 100 children “unaccompanied or separated from their families,” are trapped in a building under heavy attack.

"It is time for the world to stand up for the children of Aleppo and bring their living nightmare to an end," a spokesman for the organisation stated.

An emergency debate in the UK parliament today heard that humanitarian help is needed immediately to save lives and help those stranded in the city.

"Every hour, butcheries are carried out," the Syrian Observatory For Human Rights has furthermore claimed – as cited by CNN. The same news organisation has described the city as “a wasteland of carnage and rubble”.

The Syrian government has yet to comment on the killings in state-run media.

Conflict in Aleppo began in 2012 in the aftermath of the 2011 Arab Springs unrest.

Syrian president Bashar al-Assad has from last year been supported by Russia; rebel forces are propped up by Turkey.

Initially, world powers including the US, France, and Britain publicly backed the anti-government fighters, but the rise of Isil in the region and the rebels’ increasingly pro-Islamic tendencies eventually dissolved this support.