The UAE bombarded Yemeni rebels with air strikes on Saturday as it mourned 45 soldiers, among 50 killed in the deadliest day yet for a Saudi-led coalition fighting the insurgents.

Emirati officials vowed that the deaths in a missile attack in the battleground eastern oil province of Marib would not sap their commitment to the coalition's mission to restore exiled President Abedrabbo Mansour Hadi.

The UAE said 45 of its soldiers engaged in a Saudi-led campaign against Shiite rebels in Yemen were killed in an accidental explosion that the insurgents claimed was caused by rocket fire.

In what was the deadliest day for the coalition since it was formed in March, Bahrain said five of its soldiers guarding the Saudi border with Yemen were also killed.

A rare mass trial of 41 radical Islamists accused of seeking to overthrow the government and links with "terrorists" opened on Monday in the United Arab Emirates, official media reported.

WAM news agency said the hearing at the state security court in Abu Dhabi was devoted to procedural measures, including the appointment of lawyers.

Forces from the United Arab Emirates have rescued a British hostage held for more than 18 months by al-Qaida in Yemen, authorities in Abu Dhabi and London said on Sunday.

Douglas Robert Semple, a 64-year-old oil worker, had been kidnapped by al-Qaida in February 2014 while working in Yemen's Hadramawt province, a stronghold of the jihadist group, a statement carried by the UAE's official WAM news agency said.

Dubai's Emirates Airline said Tuesday it will resume passenger flights to the Iraqi capital in September, months after they were suspended over safety concerns.

Emirates will operate four weekly flights from Dubai to Baghdad, served by an A330-200 aircraft starting from September 17, the carrier said in a statement published by the UAE's official WAM news agency.

The United Arab Emirates condemned the "occupation" of its embassy in Sanaa by Yemen's Iran-backed Huthi rebels, the foreign ministry said in a statement demanding their immediate exit from the compound.

The embassy takeover comes as Yemeni loyalists backed by the UAE and Saudi Arabia continue advances against rebels in several southern provinces as well as in third city Taez, seen as a gateway to the rebel-held capital.

Prime Minister Narendra Modi held talks Sunday with Abu Dhabi's crown prince on bolstering cooperation with the United Arab Emirates at the start of a two-day visit, state media said.

Modi is the first Indian premier to visit the UAE in more than three decades since Indira Gandhi came in 1981 and is due to address the country's large India expat community in Dubai on Monday.

Prime Minister Narendra Modi will head to the United Arab Emirates this weekend, New Delhi's foreign ministry said Tuesday, in the first visit by an Indian premier in more than three decades.

Modi will visit from August 16 to 17 and plans to meet his UAE counterpart Sheikh Mohammed bin Rashid al-Maktoum as well as Abu Dhabi's Crown Prince Mohamed bin Zayed al-Nahyan, a foreign ministry statement said.

The United Arab Emirates is to try 41 people for allegedly seeking to overthrow the government to set up an Islamic State group-style caliphate in the Gulf state, prosecutors said Sunday.

Such mass trials on terrorism charges are rare in the UAE which has largely been spared the Islamic militancy that has hit other Arab states.

Two airplanes, one Emirati and one Saudi, landed in Aden Friday, bringing humanitarian aid to the southern Yemeni city only hours after its airport came under rocket fire from rebels.

They bring to four the number of aircraft to arrive in the port city since the symbolic reopening of the airport Wednesday, after nearly four months of fierce fighting.