Security was beefed up for the final day of the Shiite Ashura festival Sunday in south Beirut and any rumours of Hizbullah leader Sheikh Sayyed Hassan Nasrallah making a rare public appearance were quelled following Saturday’s car bomb explosion.

The heartland of Lebanon’s militant group Hizbullah was under tight surveillance in the wake of an attack on its doorstep, many concerned of another serious breach of security after two visiting Hamas operatives were killed in the blast.

While the Beirut suburbs have long-abandoned the annual ritual of self-flagellation and bloodletting that continues to take place in Amal strongholds of south Lebanon, hundreds of thousands took to the streets to march in honor of the martyrdom of Imam Hussain, the grandson of the Prophet Mohammed, who was killed in the Battle of Karbala in 680 AD.

The crowd – overseen by hundreds of plain clothes security guards – watched the giant screen projecting the image of Nasrallah, who spoke via satellite link from a hiding place instead of making a much-anticipated appearance. He did not mention the attack, but rather spoke of the continuing Israeli threat and called on Egypt to stop the blockade of the tunnel to Gaza on the final day of the 10-day festival.

A Hizbullah security official at the scene said they were on heightened alert after the blast that ripped through the Haret Hreik neighborhood, which took place on the first anniversary marking the Israeli war on Gaza. “We are being very careful after the blast,” he said, “there are lots of people here who could be targeted in an attack, especially today and especially here.”

Explosions in the area, which is almost completely controlled by the Shiite Hizbullah, are very rare and it is still unclear who is behind the attack. Nasrallah said that “there are no boundaries for Israeli terrorism, and let’s remind the world today about its crimes in Gaza and in Lebanon, its continuous threats to Jerusalem and the Palestinian population,” while calling for a withdrawal from the Gaza Strip.

He then said on the occasion of Imam Hussein’s death: “I tell Israel again that we will fight like Karbali and Husseini soldiers and we will only have victories,” while the crowds in the Haret Hreik square in Dahiyeh chanted “Death to Israel,” in their thousands.

There has been an intensifying of political rhetoric during the group’s nightly speeches over the last week, with Nasrallah accusing Israel and the US of practising “psychological warfare” against Lebanon and warning followers to defend themselves against the two states.

The blast on Saturday killed three and wounded five more. A Hamas official confirmed on local Al-Arabiya TV that two operatives of the Palestinian Islamist group were among the dead.

Police officials say explosive devices were planted in the car of Hamas representative to Lebanon Ali Barakeh, exploding just meters away from a community center where hundreds were gathered to watch Nasrallah’s televised Eve of Ashura speech.

The Sheikh has appeared in public only twice in the last three years- at the last day of the Ashura festival in 2008 and in September 2006 at a “Victory Rally” marking the end of a month-long invasion of Lebanon by Israel.