Saudi Arabia has warned its citizens to avoid visiting Lebanon, which is experiencing a worsening security and political crisis.
Tense political rivalries have worsened recently
A foreign ministry statement also urged caution to those already in Lebanon.
Riyadh is a key backer of Lebanon's pro-Western government. Past years have seen hundreds of thousands of Saudis visiting the country for holidays.
The numbers fell sharply after a series of political assassinations and the 2006 war between Israel and Hezbollah.
Lebanon is in the grip of political instability as the government and opposition are deadlocked over the appointment of a new president, a position vacant since November.
Some members of Lebanon's pro-Syrian opposition have accused Saudi Arabia of obstructing progress towards resolving the deadlock.
In the past three weeks, tension between the two sides has erupted into street clashes.
The temperature was raised last week with the killing of a top Hezbollah commander in Damascus, prompting threats of a new war with Israel.
"The Foreign Ministry advises Saudi citizens against travelling to Lebanon in view of the political and unstable security conditions that Lebanon is going through," the statement said.
Analysts said the warning might be based on intelligence or it could signal that Riyadh sees no prospect of a negotiated settlement.