Lebanese factions react to Saad Hariri's surprise resignation
In a speech broadcast on Saudi-based Al Arabiya, Hariri - who was making his second trip to the kingdom this week - said his decision was a result of rising Iranian influence in the region.
"Wherever Iran is found, we find disputes and war," Hariri said. "We will cut any hand that causes harm in our region."
Following the announcement, Lebanese President Michel Aoun's office said they received a telephone call "from outside Lebanon", in which Hariri announced his intention to resign.
The office added that it was waiting Hariri's return to find out the full "circumstances of his resignation".
Speaker of the House Nabih Berri cut short his visit to Egypt, returning to Lebanon amid the confusion.
Hariri's sudden departure, as well as the announcement of resignation from Saudi Arabia, will likely plunge Lebanon into another period of political uncertainty, after the country only just successfully agreed on a president following years of political vacuum.
Lebanese ministers and politicians rushed to Twitter to voice their concern over Saturday's sudden resignation.
Minister of Justice Salim Jreissati - affliated to the Free Patriotic Movement (FPM) - tweeted "The resignation was confusing and suspicious in its timing and location as well as the way it was delivered and the content of the resignation".
Lawmaker Walid Jumblatt tweeted: "Lebanon is too weak to bear the economic and political implications of this resignation."
"I have always been and will remain an advocate for dialogue between Saudi Arabia and Iran", he added.
Meanwhile the Minister of Economy and Trade Raed Khoury said Hariri's resignation will have little impact on the country's economy.
"There is no worry over the Lebanese pound and the financial and economic stability," he said, according to local media, adding that "Lebanon has gone through bigger crises and maintained stability".
Lebanese Forces MP Antoine Zahra said he hopes Hariri's resignation leads to "an uprising of dignity in the face of all political obstacles facing the government", according to Lebanese daily Annahar.
Zahra said recent comments by Iranian Advisor for International Affairs Ali Akbar Welayati may have promoted Saturday's resignation.
Welayati allegedly claimed that "the Syrian-Lebanese-Iraqi victory against the terrorists constitutes a victory for the axis of resistance".
"Including Lebanon in the Iranian axes without consulting with Lebanese counterparts" is a serious offence, Zahra said.
"The political stage, as Hariri said, is similar to the one witnessed before the assassination of Prime Minister Rafic Hariri", he added.
Saad Hariri is a son of assassinated billionaire Rafic, who never achieved his father's aura but fears he could suffer the same fate.
He is a vociferous critic of Iran, the powerful Lebanese Shia movement Hizballah and the regime in neighbouring Syria, which he blames for his father's killing.
The 47-year-old's political career, which has included two stints as prime minister, has been marked by his opposition to Syrian influence in Lebanon.
Hizballah which is also part of Lebanon's government, is a key backer of the Assad regime.
Born in Saudi Arabia, Hariri was running the family's vast Oger construction firm in the kingdom when his father was assassinated in February 2005.
At his family's urging, he returned to Beirut to enter politics, playing a key role in mass demonstrations that ended with the departure of Syrian forces from Lebanon after a 30-year presence.
Hariri then headed an anti-Syrian bloc to victory in 2005 legislative elections.