Yemen’s government and its two main allies have alleged in a letter to the UN Security Council that the Houthi insurgents have failed to comply with a hard-won ceasefire agreement in the vital port city of Hodeida, an Arab diplomat said Wednesday.

UN representatives from Yemen, Saudi Arabia and the UAE wrote that the Shiite insurgents had launched attacks – including sniper fire and medium-range ballistic missiles – in Hodeida even after agreeing to a ceasefire, the diplomat told AFP on condition of anonymity.

The December 31 letter to outgoing UN Security Council head Kacou Houajda Leon Adom also said the Houthis had erected barricades and dug trenches in the flashpoint Red Sea city, according to the diplomat.

Both the rebels and pro-government forces agreed in mid-December to a mutual withdrawal from the port, city and wider governorate of Hodeida at UN-brokered negotiations in Sweden.

AFP footage from Hodeida on Wednesday showed concrete barricades across the city, where some streets were lined with sandbags and piles of dirt, apparently from freshly-dug trenches.

The insurgents accused the coalition on Wednesday of flying at a low altitude over Hodeida.

They have regularly accused Saudi Arabia and its allies of attacking areas across the governorate since December 18.

Following the ceasefire deal, the UN Security Council unanimously approved a resolution authorizing the deployment of observers to oversee the truce, and a monitoring team led by retired Dutch general Patrick Cammaert arrived in Hodeida on December 23.

A UN official said the insurgents had begun to withdraw from Hodeida last week, and there have been no official UN statements on the military status of Hodeida since.

– with reporting by Agence France-Presse