SANAA, Yemen -- A Moroccan F-16 fighter jet taking part in a Saudi-led coalition targeting Shiite rebels in Yemen has gone missing, the North African nation's military said Monday, a day ahead of the start of a proposed five-day humanitarian cease-fire.
It wasn't immediately clear what happened to the jet, which the Moroccan military said vanished around 6 p.m. (1500 GMT, 11 a.m. EDT) Sunday. The Shiite rebels, known as Houthis, as well as their allies in Yemen's splintered armed forces routinely fire anti-aircraft guns at warplanes launching strikes in the country since the Saudi-led campaign began March 26.
Yemen's state news agency SABA, which is held by the rebels, did not report on the plane's disappearance. Nor was there any mention of the aircraft in Yemeni media, nor on the official website of former Yemeni President Ali Abdullah Saleh, whose forces back the Houthis.
Morroco's state news agency MAP, citing a military statement, said the pilot of a second jet said he didn't see the pilot of the missing fighter eject. The military said it had launched an investigation into the plane's disappearance, without elaborating on a cause.
Morocco has six F-16 jets stationed in the United Arab Emirates taking part in the Saudi-led coalition, which includes a group of other Sunni countries. The West say regional Shiite power Iran backs the Houthis militarily, something both the Islamic Republic and the rebels deny.
The raging conflict in Yemen has killed over 1,400 people - many of them civilians - since March 19, according to the United Nations. The cease-fire, scheduled to begin Tuesday, would help ease the suffering of civilians in the Arab world's poorest country who increasingly lack food, fuel and medicine since the bombing campaign began.
However, all sides in the conflict have warned they will resume hostilities if the cease-fire is broken.
Developments in Yemen are to be discussed at a Camp David summit this week between the United States and allied Arab leaders, but the Kings of Saudi Arabia and Bahrain have said they would not attend.
In a statement, Saudi Foreign Minister Adel al-Jubeir said Thursday's summit coincides with a humanitarian cease-fire in the conflict in Yemen, where a Saudi-led coalition is fighting Shiite rebels known as Houthis.
He said Crown Prince Mohammed bin Nayef, who is also interior minister, would lead the Saudi delegation and the king's son, Deputy Crown Prince Mohammed bin Salman, who is defense minister, will also attend.
President Barack Obama had planned to meet Saudi King Salman one-on-one a day before the gathering of leaders at the presidential retreat but the White House did not take his decision to skip the summit as a sign of any substantial disagreement with the U.S.
The king, who took power in January after his brother King Abdullah died, has not traveled abroad since his ascension to the throne.
The tiny island kingdom of Bahrain said separately that its delegation would be headed by the country's crown prince, Salman bin Hamad Al Khalifa. It did not say why the king would not attend.
Bahrain, whose leadership has close ties to the Saudis, is an important military ally of the U.S. It is the longstanding host to the Navy's 5th Fleet, which is responsible for operations around the Arabian Peninsula and northern Indian Ocean, and is Washington's main naval counterbalance to Iran.