A long-awaited indictments will embolden the opposition led by Rafik al Hariri's son, Saad, whose unity government was toppled by Hezbollah and its allies in January after he refused demands that he renounce the tribunal.
However, analysts say the increased tension is unlikely to turn violent or lead to a repeat of the 2008 sectarian clashes in which at least 85 people were killed and which brought the country to the brink of another civil war.
Hariri's March 14 coalition, which includes Christian and Druze figures, will step up pressure on Sunni Muslim Prime Minister Najib Mikati, whose cabinet is dominated by Shi'ite Hezbollah and its allies, to hand over suspects.
"The opposition is going to be fierce and will be focused on him (Mikati) more than anyone else. They consider him the soft spot in the government facing the Sunni street," Lebanese analyst Nabil Bumounsef said.
"He is exposed. The conflict between the opposition and the majority will increase.. March 14 will escalate, he will be in the middle," he added.
Hezbollah, a powerful militant movement supported by Syria and Iran, has for months been at odds with Saad al-Hariri, backed by the West and the Sunni Arab kingdom of Saudi Arabia.
Tiny Lebanon, with around four million people, has always been a battleground for bigger regional powers. Syria, which had a military presence for 29 years until 2005, remains the most influential external player in Lebanon's sectarian politics.
But most regional and international powers which have a say in Lebanon's politics are themselves facing problems and are unlikely to want to shoulder the additional burden of getting embroiled in another Lebanese crisis.
Syria's President Bashar al-Assad, a strong backer of Hezbollah, is struggling to contain a 14-week uprising against his rule, while Saudi Arabia's elderly King Abdullah has already had to address turmoil in neighbouring Yemen and Bahrain.
"If you look around you nobody wants a fight. The region is boiling in sectarian tension. So Saudi does not encourage Hariri to spark anything. It is not in its interests," a Lebanese official said.
In Lebanon itself, ordinary Lebanese showed little interest in the indictments handed over on Thursday. Life on the streets was normal on Friday, a contrast from when Mikati was appointed to form the government in January and Hariri supporters took to the streets in protest.
"Nobody in Lebanon -- the majority nor the opposition -- has the interest or the capability to make problems in the street," said Bumounsef.
Hezbollah denies any role in Hariri's killing and has said it will never allow any of its members to be handed over to the tribunal for trial.
The content of the indictments, which were not officially released, came as little surprise. Hezbollah leader Sayyed Hassan Nasrallah said last year the tribunal would target the group, and Lebanese and foreign media had mentioned two of the names which officials say were listed in the indictments.
But officials allied to Hezbollah, which say the tribunal is an Israeli tool, said they were alarmed by the timing of the indictments which were handed over as Mikati's cabinet, which was formed just two weeks ago after months of wrangling, met to agree its policy statement.
Lebanese governments traditionally deliver a policy statement before heading to parliament for a vote of confidence. The vote is expected next week.
"It is clear that the tribunal works based on politics. Its indictments and everything else related to it are designed to deliver a message," said one of the officials. "They wanted to sabotage the government and put it in an awkward position."
The carefully-worded statement "stressed the (importance of) truth in the crime against Rafik al-Hariri" and said it would monitor the progress of the court. Mikati urged Lebanese to be "reasonable and far-sighted" to ensure that "those who want to target the country and push us towards strife miss their chance".
The 2005 assassination of Hariri, seen as a Sunni leader, plunged Lebanon into a series of crises which included killings, brief internal fighting and a 34-day war between Hezbollah and Israel in 2006.
The main question is whether Lebanon is going to hand over the suspects for trial.
Hezbollah, which is both a political party and a heavily armed group, is highly secretive about its military wing, making the mission of security forces to find the suspects -- let alone arresting them -- almost impossible. "The group will not confront the state. If they want them, they need to find them first," said a Hezbollah ally.
Few people have heard of the names of the suspects or know exactly what positions they hold, even though two of them are believed to be senior figures. Even fewer people know if they were inside Lebanon.
Interior Minister Marwan Charbel said Lebanon will cooperate with the tribunal, but held out little prospect that the security forces would track down suspects.
"We can implement (the indictments) in the ways we see appropriate," he said. "There are many wanted people in Lebanon. We raid their place of work and residences and we don't find them, but we are carrying out our duties.
"We will go and raid and if we find them we will bring them and if we don't find them we will tell the judicial authorities we did not find them."
Lebanon has 30 days to try to carry out the arrests. If no one is arrested the defendants can be tried in absentia.
Hezbollah officials declined to comment but Nasrallah is expected to give a speech on Saturday.
The Future Movement, which is led by Hariri, said after meeting on Friday that it will vote against Mikati's government when parliament meets next week.
It said it considered the government's policy statement as a "coup against the tribunal" and said it "drags Lebanon into the trap of deepening the internal division and confronting the international community."