An international aid group has warned of the deteriorating humanitarian situation in Yemen's western city of Taiz, saying that corpses litter the streets and civilians are trapped.

"Sniper fire and indiscriminate shelling has trapped civilians. Dead bodies are in the streets and people are unable to attend to their most basic needs. The situation is desperate," said the head of the International Committee of the Red Cross in Yemen, Alexandre Faite on Tuesday.

Fighting in Taiz has escalated in recent days between Shiite rebels and forces loyal to the internationally-recognized government — which is backed by a Saudi-led military coalition. The rebels have imposed more than a yearlong siege.

The ICRC added that hospitals in Taiz have received an average of 200 wounded over the past 72 hours.