Clashes have erupted outside Lebanese government offices in Beirut after thousands attended the funeral of security chief Wissam al-Hassan who was killed by a car bomb on Friday.
A group of protesters tried to storm the HQ, after a new call for Prime Minister Najib Mikat to resign. Police fired warning shots and tear gas.
Friday’s attack also killed one of Wissam Hassan’s bodyguards and a woman nearby.
Opposition figures have blamed neighboring Syria for the attack.
Many have protested against Syria and its Lebanese allies amid fears the Syrian conflict could spill over.
The confrontation outside the prime minister’s office lasted for a few minutes.
Two former prime ministers – Saad Hariri and Fouad Siniora – intervened to urge their supporters to remain calm.
Lebanon’s religious communities are divided between those who support the Syrian government – including many Shias – and those mostly from the Sunni community who back the rebels.
Lebanon’s Shia militant group Hezbollah – a close ally of the Syrian government – condemned the bombing.
Syrian Information Minister Omran al-Zoubi called it a “cowardly, terrorist act”. He said such incidents were “unjustifiable wherever they occur”.
Syrian troops withdrew from Lebanon in 2005 after a 29-year-long presence, in the wake of the assassination of former Prime Minister Rafik Hariri.
Wissam Hassan, 47, was close to the 14 March opposition and the Hariri family, part of the anti-Syrian opposition.
President Michel Suleiman and Prime Minister Najib Mikati – who has faced calls for his resignation over the killing – greeted Wissam Hassan’s coffin at an earlier ceremony at the headquarters of the Internal Security Forces (ISF).
Wissam Hassan headed up the intelligence branch of the ISF. The car bomb exploded close to its offices in the east Beirut neighborhood of Ashrafiya.
He was to be buried alongside former Prime Minister Rafik Hariri.
Wissam Hassan led an investigation into Rafik Hariri’s assassination, which implicated Damascus.
He also recently organized the arrest of a former minister accused of planning a Syrian-sponsored bombing campaign in Lebanon.
A day after the bombing, Prime Minister Najib Mikati suggested the attack had been connected with that case.
Many mourners at Sunday’s funeral waved the light blue flag of the Sunni-based opposition Future Party, while others carried Lebanon’s national flag.
Many people described Wissam Hassan as a martyr who was killed trying to protect his country.
“We came for Lebanon’s future to show that we will not be scared,” said one of the mourners.
The prime minister offered to stand down as prime minister on Saturday, but President Michel Suleiman asked him to stay on in the national interest.
A prominent Lebanese opposition MP, Ahmad Fatfat, said the conflict could escalate into civil war.
“What Mr. Assad is trying to do now is transfer his problem to all the countries around Syria – to Turkey, to Lebanon, to Iraq, to Jordan, and Lebanon is the most fragile in this story,” he said.
“And maybe Assad will do what he can to transfer Lebanon into a hell situation so he can think later on that what is going on is a general war in the Middle East and not a revolution in Syria.”
Arab League Secretary General Nabil al-Arabi said he hoped the situation in Lebanon would be settled, with calm returning.
“It’s very delicate what’s going on and I hope the Lebanese, as usual, will be able to get through this difficult time,” Nabil al-Arabi said.
• Head of the intelligence branch of Lebanon’s Internal Security Forces
• Sunni Muslim born in the northern city of Tripoli in 1965
• Responsible for the security of former PM Rafik Hariri
• Viewed as being close to the Hariris and the opposition 14 March coalition
• Responsible for the August arrest of pro-Syrian politician and ex-information minister Michel Samaha