Saudi Arabia has asked its citizens to leave Lebanon due to the risk of political violence in the country, where twin suicide bombings near Iran's embassy in Beirut killed 25 people this week.
Riyadh has issued several similar calls in the past two years as the civil war in Syria has inflamed political and sectarian tension in neighbouring Lebanon.
"Saudi ambassador Ali Awadh al-Asseiri said on Thursday...that the embassy urged Saudi nationals to leave Lebanon, considering the alarming security situation," the Lebanese National News Agency reported, citing a phone call with Asseiri.
A Lebanon-based Sunni armed group close to al-Qaeda has claimed responsibility.
"This is a double-martyrdom operation carried out by two heroes from the heroic Sunnis of Lebanon," Sirajeddin Zreikat, a member of the group, wrote on Twitter.
"Operations will continue in Lebanon until two demands are met: first, withdrawing Hezbollah members from Syria; second, release our prisoners from jails of injustice in Lebanon."
Fighters from the Shia group Hezbollah fought alongside Assad's forces in several strategic battles in Syria against mainly Sunni Muslim rebels. Iran has been bank-rolling Assad's fight, and also supports Hezbollah in Lebanon.
There have been several bomb attacks in Beirut and the northern city of Tripoli linked to the conflict in neighbouring Syria.