CAIRO — Egypt extended Saturday its participation in the Saudi-led Arab coalition carrying out air strikes on Iran-backed Shiite rebels in Yemen for another six months, the presidency said.

"The National Defence Council agreed to prolong the participation of (Egyptian) troops engaged in a combat mission" in the Gulf, the Red Sea and the Bab al-Mandab Strait, a statement said.

At the beginning of May, the authorities renewed the mandate by three months, and Saturday's statement said the current one will "last for six months, or until the end of the combat mission" if that happens first.

It said the purpose of the mission was to "defend Egyptian and Arab national security".

President Abdel Fattah al-Sisi has previously said that Cairo's objective is to secure navigation in the Red Sea and through the strategic strait, which gives access to the Suez Canal, a key source of revenue.

Egyptian air forces have been involved in the coalition since the first strikes were launched on March 26 against the Huthi rebels who have seized much of Yemen's territory