AsiaNews reports that the peaceful rally began with welcoming words from Ghassan Tueni who invited the crowd to repeat the oath pronounced by Tueni's son Gibran - also assassinated in December 2005 - after Hariri's murder: "Never again war between Christians and Muslims."
Waving flags, handkerchiefs and balloons in the blue colour of Lebanon's ruling coalition, the crowd shouted slogans against Syria and its Lebanese allies.
At exactly 12:55 pm - the time of Hariri's assassination - the crowd fell silent except for a muezzin making the Islamic call to prayer and the tolling of church bells.
Lebanese army units were deployed in the area, including armed vehicles, and a two-metre barbed wire barrier separated Martyrs Square, where Hariri's tomb is located and where the rally took place, from Riad al-Solh Square where about a hundred opposition supporters have been on a sit-in since 1 December.
Druze leader Walid Jumblatt did not mince words and accused Syria of being behind the spate of political murders that have occurred in Lebanon in recent years.
"This year," he said, "the tribunal will come and with it retribution," Jumblatt said in a reference to the international tribunal agreed to by the UN and the Lebanese government.
He was referring to the international tribunal agreed to by the United Nations and the Lebanese government. The tribunal is expected to look into political crimes perpetrated in the country since 2004 and which most likely triggered the country's current political crisis in November of last year.
Saad al-Hariri, ruling coalition parliamentary leader and son of the slain former premier, attacked the main opposition party, Syrian- and Iranian-backed Hezbollah but also called for a dialogue with opposition leaders.
"We are ready for every courageous decision for the sake of Lebanon and for the sake of a solution in Lebanon, but the international tribunal is the only passage for any solution," he said.
Meanwhile, Vatican secretary of state, Cardinal Tarcisio Bertone, has condemned a 13 February bus bomb attack in a strongly Christian area outside Beirut that killed three and wounded 30 people.
Pope Benedict also renewed his appeal for an end to violence in Lebanon imploring the Lebanese people to "unanimously reject violence" and use the latest tragedy as an impetus to peaceful resolution of their conflicts.
Some 300,000 people flock to Beirut to remember Hariri (AsiaNews, 14/2/07)
Blasts in Christian area outside Beirut leave three dead, 30 wounded (Catholic News, 14/2/07)
End violence in Lebanon, Pope pleads (Catholic World News, 14/2/07)
Benedict appeals again to end Mid-East violence (CathNews, 29/1/07)
War begins with words, warns Lebanese Cardinal (CathNews, 12/12/06)
Lebanese Maronites call for fresh presidential elections (CathNews, 7/12/06)
800,000 mourn Maronite Lebanese leader (CathNews, 24/11/06)
Lebanon on brink over assassination (CathNews, 22/11/06)
Lebanon's Maronite bishops reject call for new govt (CathNews, 6/10/06)
New Gaza settlement tenders concern Caritas Jerusalem (CathNews, 8/9/06)
Lebanon's "hell on earth": Order of Malta (CathNews, 29/8/06)
Stay in Lebanon: Maronite Archbishop begs his flock (CathNews, 22/8/06)
Bishops and church groups welcome Middle East ceasefire (CathNews, 14/8/06)
Neither retaliation or provocation can justify slaughter: Australian Maronite nun (CathNews, 11/8/06)
Aid agencies call on PM to push for Middle East ceasefire (CathNews, 7/8/06)
Unity and hope amid chaos in Lebanon (CathNews, 2/8/06)
Canberra Christian leaders slam Govt over "cowardly" silence on Middle East (CathNews, 1/8/06)
Benedict calls for miracle as Qana toll reaches 54 (CathNews 31/7/06)
Asian and African migrants "abandoned" in Lebanon, Vatican says (CathNews 27/7/06)
Students taking lead for Middle East peace (CathNews 26/7/06)
Lebanese Maronite bishops plea for UN help (CathNews 25/7/06)
Caritas Lebanon slams milk factory attack (CathNews 21/7/06)
Advertise Lebanon evacuation plans, stranded priest tells Govt (CathNews 20/7/06)
Biblical lamentations as Gaza descends into disaster (CathNews, 12/7/06)
15 Feb 2007