On a shimmering, sunny day, a hearse carrying the coffin of a slain journalist and outspoken critic of Syria made its way through Beirut's Martyrs' Square, a place where he had raised his voice in fevered calls for freedom only weeks before and where throngs of mourners gathered to honor him Saturday.

Samir Kassir, 45, a columnist for Lebanon's An Nahar daily, was killed Thursday when a bomb exploded under his car near his home in the capital. The killing, three months after the assassination of former Lebanese prime minister Rafiq Hariri, firmed up the resolve of a coalition of opposition groups to press for the ouster of the Lebanese president, Emile Lahoud.

The funeral procession stopped briefly by the seafront offices of An Nahar, which overlook the scenic reconstructed center of Beirut and the Mediterranean, then made its way to a Greek Orthodox church. Leading politicians, members of parliament, diplomats, along with journalists, students, family and friends attended the service.

"Nations are not known for their size, but for their message," Archbishop George Khodr said in eulogizing Kassir. "Your God made of you a forerunner, and we cannot change that. Before the evildoers eclipsed you, you bore witness to their deeds."

The granddaughter of An Nahar's founder, Ghassan Tueni, pledged that the youth of Lebanon would carry forward Kassir's torch of bravery and free expression.

"Our pain is the pen that will not be broken," Nada Tueni said, telling mourners how Kassir had mentored her and other young journalists at the newspaper.

"How many heroes must we lose, how many resources?" she asked.

Kassir's wife, Giselle Khoury, a well-known talk show host, and two daughters from a previous marriage, Liana, 16, and Maissa, 20, sobbed and shook with grief as they hung on to the coffin before he was laid to rest in the Mar Mitr cemetery.

Khoury has requested an international investigation into the killing of her husband, who was a dual French and Lebanese national. An FBI team and a crew of French police investigators arrived in recent days to inspect the bombing site outside Kassir's home.

Walid Jumblatt, a Druze chieftain, said "a peaceful and civilized sit-in" scheduled to begin Monday at the gates of the presidential palace would continue until the Syrian-backed president step down. Jumblatt warned that more political killings were likely and advised key political and religious figures to take precautions.

Syria, which maintained a military presence in Lebanon for 29 years, withdrew its troops in April but still exerts influence in the country, especially through the intelligence services and political allies, including Lahoud.

Syrian officials have denied any role in the Kassir's death.

Born to a Syrian father and a Palestinian mother, Kassir had become the voice of conscience among supporters of modernity and democracy in the Arab world. He had also criticized human rights violations and the incarceration of political dissidents in Syria. He had also written abrasively about the need for reforms in Syria.

"They killed our Samir," which also means "our nighttime companion" in Arabic, read a white satin banner across a massive wreath of red and white roses near the altar of the church. It was signed by "Syria's intellectuals."

On Sunday, the second round of Lebanon's four-round parliamentary elections are to take place in southern provinces and towns. Slates drawn up by the Shiite Hezbollah movement and House Speaker Nabih Berri's Amal movement are expected to win all 23 seats there, 18 of which are reserved for Muslims and five for Christians. The first round of voting took place last Sunday in Beirut.

Mourners gather in Beirut's St. George Cathedral for the funeral of journalist Samir Kassir, killed Thursday by a bomb.A woman weeps as she looks at Kassir's photo in a Greek Orthodox cemetery.