Three Gulf states advised their citizens against travelling to Lebanon on Thursday and asked those already there to leave as soon as possible.
The official Saudi Press Agency, citing an official Foreign Ministry source, said the kingdom was asking citizens who were visiting or residing in Lebanon to leave as soon as possible.
Kuwait and the United Arab Emirates also warned nationals against travel to Lebanon via official news agencies later in the day. Bahrain had urged its citizens to leave Lebanon on Sunday.
Lebanese Prime Minister Saad al-Hariri resigned on Saturday while in Saudi Arabia, accusing Iran and the Lebanese Shia group Hezbollah of sowing strife in Arab states and saying he feared assassination.
The Saudi minister for Gulf affairs has accused Lebanon of declaring war against the kingdom, and alleged that the Lebanese Shia group Hezbollah was involved in firing a missile at Saudi Arabia from Yemen on Saturday.
French President Emmanuel Macron announced that he would make a previously unscheduled trip to Saudi Arabia on Thursday to see Crown Prince Mohammed bin Salman and discuss "regional questions, in particular Yemen and Lebanon".
*This story was edited by Ahram Online.