Gunmen assassinated a senior prosecutor and a judge in a restive province in northwest Syria on Sunday, the country's state news agency said, while activists reported that security forces shelled rebel-held areas in the besieged city of Homs.

SANA news agency said gunmen opened fire in the morning on a car carrying Idlib provincial state prosecutor Nidal Ghazal and judge Mohammed Ziadeh.

The Syrian army has been laying siege to the ancient city of Palmyra, a world heritage site, since early February and shooting at anything that moves from a historic citadel, residents say.

"Palmyra is surrounded by the army from all fronts: the Arab citadel, the olive and palm tree groves, the desert, the city," one resident told AFP by telephone, adding that the operation began on February 4.

Progressive Socialist Party leader Walid Jumblat noted that it would be unacceptable for Lebanon to remain idle in its approach towards Syrians who have fled to Lebanon to escape their country’s crackdown against anti-regime protests, reported the daily An Nahar on Sunday.

He told the daily: “They should be granted aid and social guarantees regardless of their numbers.”

Iraq is taking measures to secure its border with Syria against weapons smuggling and the unauthorized movement of people, Prime Minister Nouri al-Maliki's office said in a statement on Saturday.

Syrian President Bashar Assad's regime has been carrying out a bloody crackdown on an uprising in which human rights groups say more than 6,000 people have been killed since March 2011.

Hollywood star Angelina Jolie said Saturday the world should intervene to stop the violent crackdown in Syria and condemned powers that have vetoed a U.N. resolution against the regime.

"I think Syria has got to a point, sadly, where certainly some form of intervention is absolutely necessary," Jolie told al-Jazeera Balkans in an interview shown on the channel's Internet site.

Swiss authorities have intercepted mobile phone surveillance equipment destined for Syria and Iran, an official told Swiss Television.

Juergen Boehler from the State Secretariat for Economic Affairs (SECO) told the German channel's "10 vor 10" program European suppliers had tried to send the goods via Switzerland but customs officials seized them at the border.

The Hizbullah leadership in the South and top members of Amal in Jabal Amel backed on Saturday Syrian President Bashar Assad’s reform efforts which they said aim at consolidating the country against foreign plots.

Following a meeting they held at Hizbullah’s offices in Tyre, the two sides said in a statement that the attempts to target Syria’s stability and the unity of its people and army are aimed at hindering its support for the Palestinian people and their right to liberate their land.

Embattled Syrian president Bashar Assad's forces unleashed their heaviest pounding yet of the central protest city of Homs, monitors said, as thousands rallied for his ouster.

The protesters emerged from mosques after the main weekly Muslim prayers on Friday, including in Damascus, following a call by Internet-based activists for a rally for a "new phase of popular resistance."

U.S. military and intelligence drones are reportedly monitoring the Syrian military's deadly crackdown on opposition forces and protestors.

U.S. defense officials told NBC News' Jim Miklaszewski that "a good number" of unmanned drones are monitoring the activities of the Syrian regime.

Chinese Vice Foreign Minister Zhai Jun called on all sides in Syria to stop the violence and said elections should go ahead peacefully after Damascus talks with President Bashar Assad Saturday, state media said.

"The position of China is to call on the government, the opposition and the rebels to halt acts of violence immediately," Zhai said, adding that it was vital that "calm be restored as quickly as possible as that serves the interests of the Syrian people."