An Emirati fighter jet taking part in a combat mission against Houthi rebels in Yemen went down, killing the two pilots aboard.
It is the first known case of an Emirati jet from the Saudi-led coalition fighting the rebels being lost since the campaign began in March last year.
Two UAE pilots were killed in the crash, which was caused by a "technical failure", the coalition said in a statement.
It did not say when and where the plane went down.
However, security officials in Yemen's southern city of Aden said the jet crashed on Monday in the city's western district of al-Buraiqeh, where parts of its wreckage were found.
The jet went down after hitting a mountain in the area while flying low on a mission against insurgents believed to be members of al-Qaeda, the officials added, speaking on condition of anonymity.
Yemen has been torn apart by conflict for the past two years. More than 6,100 people have died - half of them civilians - since the Saudi-led coalition launched air strikes on Yemen in March 2015, according to the UN.
The conflict has led to a humanitarian crisis across the country.
More than 21 million people are in need of humanitarian assistance, while the World Health Organization has warned that Yemen's healthcare system is "on the brink of collapse".