Supporters of Syrian President Bashar al-Assad are taunting starving residents of the besieged town of Madaya with pictures of food. The town in northern Syria has been besieged by forces loyal to Assad and Lebanese militia Hezbollah since July, which have blocked all aid transportations from reaching the town, human rights groups allege.

Hijacking the Twitter hashtag "solidarity with the siege of Madaya", supporters of Assad and Hezbollah tweeted pictures of plates laden with food at the residents of the town, where according to medical charity Medecins Sans Frontieres 23 people died of starvation in the past month.

Activists claim the town's 40,000 residents have been forced to eat dogs and cats, and even rubbish, and pictures on Twitter show emaciated children and the bodies of starvation victims.

The town was besieged in response to the blockade and starvation by rebels of Koah and Kafrya, two government-held towns in Idlib province. Assad's forces claim a rebel group in control of the city has seized aid deliveries.

According to local doctors, 13 people have been shot dead by regime forces as they ventured from the town to scavenge for food. The Red Cross says some food is available in the town but at a hugely inflated price.

The UN said it was previously denied permission to deliver aid to the town, but that a deal had now been reached with Damascus. On 10 January, UN officials told the BBC that negotiations to ensure aid reaches the town by 11 January are ongoing.

"While the Syrian government finally conceded that it would allow aid into Madaya, it shouldn't take starving children and media outrage for aid to be delivered," Nadim Houry, deputy Middle East and North Africa director of Human Rights Watch, said. "Countries backing a political solution in Syria need to push the warring parties to allow aid to all those suffering in Syria."