SANA, Yemen — The United Arab Emirates said on Friday that 45 of its soldiers were killed fighting Houthi insurgents in a province east of Yemen’s capital, in a major setback for the coalition of Arab forces that have been trying for months to vanquish the rebels.

The death toll was the largest in a single day for the military of the United Arab Emirates, the Persian Gulf nation that has assumed a central role in the Saudi-led coalition seeking to restore Yemen’s exiled government to power.

A statement carried by a Houthi-run news agency said that the deaths came after the rebels fired what it called a ballistic missile at a military base used by the coalition in Marib Province, striking an arms depot and destroying other equipment, including Apache helicopters.

Bahrain, another member of the Saudi coalition, said on Friday that five of its soldiers also had been killed.