BEIRUT • Lebanon believes its former prime minister, Mr Saad al-Hariri, is being detained in Saudi Arabia, with President Michel Aoun demanding his immediate return to Beirut.

Mr Aoun told Saudi Arabia's charge d'affaires Walid Al Bukhari in a meeting at the presidential palace that the way Mr Hariri resigned from Riyadh last Saturday was "unacceptable", the state-run National News Agency reported yesterday.

Top government officials in Beirut have said Mr Hariri is being held against his will, amid a deepening crisis pushing Lebanon onto the front lines of a power struggle between Saudi Arabia and Iran.

But United States Secretary of State Rex Tillerson said Saudi Foreign Minister Adel al-Jubeir had assured him Mr Hariri had resigned of his own accord, while French Foreign Minister Jean-Yves Le Drian told Europe 1 radio yesterday: "He (Mr Hariri) went to Abu Dhabi the day before President (Emmanuel) Macron's visit (on Wednesday), so we think he's free to move around."

And a German Foreign Ministry spokesman said it assumed Mr Hariri "chooses where he goes".

Egyptian President Abdel Fattah al-Sisi said on Wednesday he was opposed to any war with Iran and its Lebanese proxy, the Hizbollah militant group, and that Gulf tensions should be handled cautiously.

"Our point of view when it comes to new troubles with either Iran or Hizbollah or any other issue is that we have to deal with great care so as not to add to the challenges and troubles of the region," Mr Sisi said. "I am against war."

REUTERS, WASHINGTON POST, BLOOMBERG, AGENCE FRANCE-PRESSE