Yemen government forces backed by the Arab coalition launched an offensive on the rebel-held port city of Al Hodeidah on Wednesday morning.
The military operation, known as Golden Victory, is intended to liberate the city from the Iran-backed Houthi militia, but It was launched only after “exhausting all peaceful and political means”, said Yemen's government in a statement carried by the state-run Saba news agency.
"The liberation of Al Hodeidah port is a turning point in our struggle to recapture Yemen from the militias that hijacked it to serve foreign agendas.
"The liberation of the port is the start of the fall of the Houthi militia and will secure marine shipping in Bab Al Mandab strait and cut off the hands of Iran, which has long drowned Yemen in weapons that shed precious Yemeni blood."
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Al Arabiya television also reported that an offensive had been launched, but there was no immediate word from the state media in either Saudi Arabia or the UAE.
The Arab coalition — which includes Saudi Arabia and the UAE — intervened in the Yemen war in 2015 at the request of the internationally-recognised government of Yemeni President Abdrabu Mansur Hadi.
A resident in Al Hodeidah told The National on Wednesday morning that UAE naval ships are stationed off the coast of the city and shelling Houthi hideouts.
"The UAE forces launched more than five air strikes at Houthi vessels carrying explosives at the Al Hodeidah harbour," Saleh Al Dubia, an Al Hodeidah-based journalist, told The National.
More on the Hodeidah offensive
UAE's Minister of State for Foreign Affairs Anwar Gargash earlier told French newspaper Le Figaro the deadline for a withdrawal from Al Hodeida by the Houthis expired early on Wednesday morning.
"We gave UN special envoy Martin Griffiths 48 hours to convince the Houthis to withdraw from the port and city of Al Hodeidah," Dr Gargash said.
UN chief Antonio Guterres had said that Mr Griffiths was in "intense negotiations" in an attempt to avoid a military confrontation. However, the Houthi rebels have repeatedly refused a deal to hand over control of the Al Hodeidah port to UN-monitored international forces.
The UN and International Committee of the Red Cross said on Wednesday that all parties in Yemen’s war must protect civilians.
"Under international humanitarian law, parties to the conflict have to do everything possible to protect civilians and ensure they have access to the assistance they need to survive," Lise Grande, UN humanitarian coordinator for Yemen, told Reuters by e-mail.
In Geneva, ICRC spokeswoman Marie-Claire Feghali said that development will "likely to exacerbate an already catastrophic humanitarian situation in Yemen ", where water and electricity networks are vital to the civilian population's survival.
The Arab coalition has repeatedly said that it will protect Al Hodeidah's lifeline and seek to secure the lives of civilians.
Al Hodeidah, the second largest port in the country, is the main conduit for humanitarian supplies into a country teetering on the brink of famine. The Houthis have been using the port to smuggle weapons into the country.
Khalid bin Salman, Saudi Arabia's ambassador to the US, noted on Wednesday that the Houthis kept obstructing mediation efforts and rejecting a plan to hand over Al Hodeidah to the UN.
"The most effective solution to the situation in Al Hodeidah, and in Yemen, is for the Houthi militias to adhere to UNSC resolution 2216, which calls for the unconditional Houthi withdrawal from all occupied cities," he tweeted.
"Due to the continued obstruction by the Iranian-backed Houthis of mediation efforts, the former UN envoy to Yemen proposed a plan to hand over control of Hodaidah to the UN.
"The Yemeni government and the coalition have accepted the proposal. Unfortunately, the Houthis, spurred by Iran, rejected this initiative as it did to all other initiatives. The Coalition remains supportive of UN efforts to implement its plan."
The Houthi militia has repeatedly fired missiles at Saudi Arabia, which the United States and UN experts say are of Iranian origin, a claim Tehran denies.
On Wednesday morning, the Arab coalition said that Saudi air defences intercepted a ballistic missile that was fired by the Houthi rebels in Yemen towards the kingdom,
The projectile was fired from Yemen’s Saada province towards the Saudi city of Jizan “intentionally targeting” residential areas, said coalition spokesman Turki Al Malki in a statement carried by the state-run Saudi Press Agency. He said that no one was injured in the incident.
More than 10,000 people have been killed in Yemen's civil war, while the UN says Iran has supplied the Houthis with weapons from assault rifles up to the ballistic missiles.