|Mikati's nomination prompted protests from Hariri supporters who declared January 25 'a day of rage' [Reuters]
All roads have been opened and barriers removed in the Lebanese capital after two days of protests, security officials say.
Calm returned on Wednesday as talks on forming a new government continued in Beirut.
The previous day, Michel Sleiman, the Lebanese president, formally appointed Najib Mikati, a billionaire businessman, as prime minister-designate and asked him to form a new government.
Parliament members voted to back Mikati, the candidate Hezbollah had proposed as a prime minister. Hezbollah, which enjoys the overwhelming backing of the country's Shia Muslims, has a parliamentary faction as well as a powerful military wing.
Mikati gained 68 votes to Hariri's 60, putting the Hezbollah-led opposition in a position to form a government.
Mikati, 55, has said he wants to form a unity government. Even though Hezbollah backed him, he is seen as a relatively neutral figure who enjoys good relations with both Bashar al-Assad, the Syrian president, and Hariri, although the latter has said he would not be part of any new unity government.
Day of rage
The defeat of Saad Hariri, who had been prime minister since 2009, came as Sunni Muslims protested against Mikati's nomination and condemned the rising power of Syria and Hezbollah in a "day of rage"acoss the country.
The Lebanese army fired bullets into the air in the northern city of Tripoli to control hundreds of protesters who burned tyres and blocked roads. They also torched a van belonging to Al Jazeera.
In a televised statement, Hariri later tried to calm the anger that had poured onto the streets. "I understand the shouts of anger that have come out of your chests," he said.
"But it is not right that this anger leads us to what is against our values and upbringing and our belief that democracy is our only resort and the only way we express our political stance," he said.
The Harvard-educated Mikati began building his business in the midst of Lebanon's 1975-90 civil war [Reuters]
"Raise the Lebanese flag high above your head and know that I will always be with you."
Al Jazeera's Zeina Khodr, reporting from Beirut, said that the protests were quick to break out after the announcement that Mikati had won a majority of parliamentary votes.
"People have come onto the streets, especially in strongholds of Saad Hariri, demonstrating against the selection of Mikati," she said.
She said that several districts of northern Lebanon were rocked by protests by supporters of the March 14 coalition, led by Hariri.
Mikati portrays himself as a consensus candidate who can work with all of Lebanon's rival political camps.
"I will co-operate fully with all Lebanese to form a new government that protects the unity and sovereignty of our country," Mikati said on Tuesday after learning of his nomination.
He was chosen as caretaker prime minister in April 2005, when an outcry over Rafiq al-Hariri's killing forced Syria to withdraw its troops from Lebanon.
Mikati served three months until the election won by an alliance of Sunni, Druze and Christian parties led by Hariri's son, Saad.
Mikati served as minister of public works and transport in three cabinets between 1998 and 2004.
Hassan Nasrallah, the Hezbollah leader, urged Mikati to form a national partnership government.
"We have supported the nomination of ... Mikati and we call on him to form a national partnership government. The Lebanese have a chance to close ranks," Nasrallah said in an address to thousands of supporters on Tuesday.
While Catherine Ashton, the European Union's foreign policy chief, called on Mikati to "broadcast possible consensus in forming his government", having a Hezbollah-backed prime minister is especially problematic for the US, which views the party as a terrorist organisation.
The White House is considering exactly how to respond to the new government forming this week in Beirut and has opened a review into its assistance programs to the country.
Cuts or realignment to political, economic and military aid to Lebanon are likely if Hezbollah takes a major governmental role, officials said. The US has imposed sanctions against the group and its members, who US officials are barred from meeting.
"A Hezbollah-controlled government would clearly have an impact on our bilateral relationship with Lebanon," Hillary Clinton, US secretary of state, said.
"Our bottom lines remain as they always have been. First, we believe that justice must be pursued and impunity for murder ended.
"We believe in Lebanon's sovereignty and end to outside interference. As we see what this new government does, we will judge it accordingly."
Hariri's government collapsed when Hezbollah and its allies pulled out 11 ministers from the cabinet in a dispute over the Special Tribunal for Lebanon, which is investigating the 2005 murder of Saad's father and the country's former prime minister, Rafiq al-Hariri.
Nasrallah has accused the Netherlands-based tribunal of being under US-Israeli control.
He has also said he expects the tribunal will implicate Hezbollah members and warned of grave repercussions.
Many fear Hezbollah will react violently if its members are indicted, as is widely expected
Mustafa Alloush, a member of Hariri's Future bloc, told Al Jazeera that people were angry because they believe that Hariri is the legitimate prime minister and that they "feel that their pride has been injured by the way things have been done".
Alloush, a former MP, told Al Jazeera that Hariri would not co-operate because under the present circumstances, a true unity government would not be possible.
"The way things are going, any new cabinet would be under the hegemony of Hezbollah" he said.
"And Hezbollah wants one thing: the withdrawal of Lebanon from the tribunal and ... they want Lebanon to be part of the Syrian-Iranian alliance."