Lebanon's opposition March 14 coalition has encouraged a massive turnout for Sunday's funeral for the slain intelligence official Wissam al-Hassan, and for a "day of rage" against Syrian President Bashar al-Assad.
Saad al-Hariri, leader of the opposition, has urged all of Lebanon to attend the funeral in central Beirut, an appeal which could transform the ceremony into a powerful political rally.
"Every one of you is personally invited tomorrow to Martyrs' Square to the prayers for Wissam al-Hassan"
- Saad al-Hariri
Friday's bombing, which according to officials left two others dead and scores more wounded, has added to fears of renewed sectarian violence in the country, still scarred from a long civil war.
Protests erupted in several cities the day after three people, including Hassan, a senior security official opposed to the Syrian regime, were killed in a car bombing in the Lebanese capital.
"Every one of you is personally invited tomorrow to Martyrs' Square to the prayers for Wissam al-Hassan," Hariri said in a statement broadcast by Future Television on Saturday.
"All of Lebanon, which Wissam al-Hassan protected from the plots of Bashar al-Assad and Ali Mamlouk ... exposing himself so that you would not be blown up."
Hariri was referring to the Syrian president and a Syrian general indicted in August over an alleged bomb plot in Lebanon.
Demonstrators and armed men blocked roads with burning tyres in Beirut on Saturday, while soldiers opened fire on a group who took over a road in the Bekaa Valley, wounding two people, witnesses said.
Much of Lebanon is divided between those that support Assad and those that back the rebels seeking to topple him in the country's bloody 19-month conflict.
The March 14 alliance called on Lebanon's government to resign over the attack, which it blamed on the Syrian regime.
PM's resignation offer
After an emergency cabinet meeting, Najib Mikati, Lebanese prime minister, said he had offered his resignation but that President Michel Suleiman has asked him to stay on for a "period of time".
"I assured the president of the republic that I was not attached to the post as head of the government," Mikati said.
"He asked that I stay in place because it is not a personal issue but one of the national interest."
|Demonstrators blocked a road in the southern city of Sidon on Saturday to protest against the bomb blast[AFP]
Mikati said the blast was linked to Hassan's recent case in which he exposed an alleged plot by Syria to sow chaos in Lebanon.
Hassan, intelligence chief of the Internal Security Forces (ISF), headed an investigation over the summer that led to the arrest of Michel Samaha, a former information minister and ally of Assad, accused of trying to help smuggle explosives into Lebanon.
Hassan had also led an investigation that implicated Syria and its principal Lebanese ally, the Hezbollah, in the assassination of former prime minister Rafik al-Hariri.
Saturday was declared a day of mourning and Hassan is to be buried on Sunday alongside Hariri, murdered in a car bombing seven years ago.
The funeral will be held after Muslim prayers at the al-Amine Mosque in central Beirut.
Friday's blast, which also wounded at least 80 people, drew condemnation from abroad, with Hillary Clinton, US secretary of state, calling it a "dangerous sign that there are those who continue to seek to undermine Lebanon's stability".
Omran al-Zohbi, the Syrian information minister, condemned what he called a "terrorist, cowardly" attack. Such incidents were "unjustifiable wherever they occur," he said.
However, both Saad Hariri and Walid Jumblatt, the influential Druze leader, accused Assad of being behind the bombing.
"We accuse Bashar al-Assad of the assassination of Wissam al-Hassan, the guarantor of the security of the Lebanese," Hariri said.
Major-General Ashraf Rifi, head of the ISF, described Hassan's death as a "huge blow" and gave warning that further attacks were likely.
"We've lost a central security pillar," he told Future Television.
"Without a doubt, we have more sacrifices coming in the future. We know that, but we will not be broken."
The tension was palpable in Beirut as soldiers and police guarded street corners in the Ashrafiyeh area on Saturday, the mainly Christian neighbourhood where the bomb exploded during rush hour, and at Martyrs' Square in the centre.
In the northern city of Tripoli, where Syria-related tensions are running high, one person was killed on Friday night after clashes erupted between the rival districts of Jabal Mohsen and Bab al-Tabbaneh.
Jabal Mohsen is populated by mostly Alawites supportive of Assad, while Bab al-Tabbaneh is a Sunni area mainly sympathising with the opposition.
Al Jazeera's Hoda Abdel-Hamid, reporting from Tripoli, said gunfire had been heard in the city on Saturday morning after armed groups urged shopkeepers to keep stores shut.
"People on the street tell us that armed men on motorcycles were shooting in the air, warning shopowners that they must stay shut today," she said.
The main highway from Tripoli to the Syrian border was shut down, with protesters burning tyres in the Akkar area.