Staring from behind rusted bars in a dirty cage, these are the three lions who are 'close to death' after being reduced to skin and bone in the middle of war-torn Yemen.   

The lives of the animals are hanging by a thread after campaigners said food supplies at Sana'a Zoo are so scarce that the lions are being fed just once a week as the staff are unable to afford more as the civil war rages on.

The three lions, named Ward, Frence and Moklees, are in a critical condition and are among scores of other animals at the zoo living in squalid conditions.

Video footage and photographs of the starving lions show how feeble they are and you can hear their cries of hunger.

Their cages have not been cleaned and are so dirty that the lions now have skin conditions such as mange, which is caused by mites, and bacteria infections. 

The smell of their enclosures is so bad that campaigners have described 'the smell of death', with one saying the smell burned his nose and he was unable to stay for long to take pictures and videos of the animals.

The lions are also so weakened that the vet must provide vitamins and medication - but these are in short supply due to the war.

Campaigners are now most concerned about the lion Ward. 'He is the one who is clearly the most sick and starving of all of the animals,' campaigner Diane Housel said. 

Sana'a zoo is home to around 700 animals - including around 30 lions - but with Yemen in a bloody war since 2014 the zookeepers are unable to afford cleaning supplies which are key to killing off deadly bacteria or food, medication or vitamins for the animals.  

With 80 per cent of the population in Yemen dependent on international food aid and the country facing a famine, the animals at the zoos are not a priority. 

The zoo is unable to afford a substantial amount of food - and campaigners say the lions are often fed dead animals from the villagers, such as a cow or old donkey.