Four suspects were named in the UN-backed Special Tribunal for London (STL) investigating the 2005 murder of Rafiq Hariri, the former Lebanese prime minister, Marwan Charbel, the country's interior minister, has said.
Said Mirza, Lebanon's prosecutor-general, had issued arrest warrants for Mustafa Badreddine, Salim Ayyash, Assad Sabra and Hussein Anaissi, Charbel told the AFP news agency on Friday.
The whereabouts of the suspects, who have been described as senior members of the Hezbollah movement, are unknown.
Lebanon remained calm and stable a day after the indictments were issued.
"So far things have been very quiet," said Al Jazeera's Charles Stratford, reporting from Beirut, on Friday.
"There has been drips of reaction coming through from some officials but nothing concrete yet."
Media reports had spoken of a possible backlash after the indictments.
Badreddine, one of the suspects, is the brother-in-law of top Hezbollah operative Imad Mughniyeh, who died in a 2008 bombing in Damascus, the Syrian capital.
He is suspected of having masterminded the February 14, 2005 seaside bombing that killed Hariri and 22 others.
Ayyash, another senior party official who holds US citizenship, allegedly carried out the attack.
Sabra and Anaissi allegedly co-ordinated with Ahmad Abu Adas, a Palestinian who contacted Al Jazeera television following the Hariri assassination to claim responsibility for the bombing.
Charbel said a meeting among all concerned security services was planned on Saturday to co-ordinate search operations for the suspects.
Calls for stability
Hillary Clinton, the US secretary of state, praised the STL for its decision.
In a statement on Friday she said: "We understand that this is an emotional and significant period for all involved, and we call on all parties to promote calm and continue to respect the Special Tribunal as it carries out its duties in a professional and apolitical manner."
Clinton called "on the government of Lebanon to continue to meet its obligations under international law to support the Special Tribunal".
Walid Jumblatt, a Druze leader and influential MP, said Lebanon's stability was of critical importance.
"I call upon all political powers to overcome minor situations for the national interests on top of the national agenda; get rid of any elements that might cause rift and tension and to leave the government, political powers and state agencies to do their job," he said.
Hezbollah, which has three members in the current parliament, forced the collapse of Saad Hariri's, Rafiq's son, government in January after he refused to stop co-operating with the STL.
The group and its allies resigned from Hariri's unity government just days before the tribunal prosecutor filed his petition for the indictments to a pre-trial judge.
The tribunal was set up in The Hague in 2009 by the UN to try those alleged to have carried out the deadly bomb attack.
Hisham Jaber, a retired Lebanese army general, told Al Jazeera from Beirut that he did not think those named in the indictments would be arrested.
"Hezbollah denied its relation with this crime since the beginning," said Jaber, without speculating on who would be named.
"Those people, whether they are members of Hezbollah or close to Hezbollah, I don't think the Lebanese authority has the ability to arrest them if they are still in Lebanon.
"I think this mandate will stay open until those people will deliver themselves to the criminal [court]."
Fares Soueid, a leading member of Saad Hariri's Western-backed March 14 coalition, told the AFP news agency: "This is a big day for Lebanon ... We have been waiting for this for six years. We hope that justice will be served and that Lebanon will be able to look toward a more stable future."
The indictments have been twice amended while the pre-trial judge assessed whether there was enough evidence to proceed with a trial.
'Responsibly and realistically'
Saad Hariri's successor, Najib Mikati, who was appointed with the blessing of Hezbollah, said the government would deal with the indictments "responsibly and realistically".
"Today we are facing a new reality that we must be aware of ... bearing in mind that these are accusations and not verdicts," Mikati said at a news conference. "All suspects are innocent until proven guilty."
Hezbollah has said the international court is a tool of the United States and Israel and wants Lebanon to halt all co-operation with it, including withdrawing Lebanese judges and ending its share of funding for the court.
Lebanon now has 30 days to serve out the arrest warrants. If the suspects are not arrested within that period, the tribunal will then make public the indictment and summon the suspects to appear before the court.