Syrian and local children release balloons and form the word "Syria" with candles during a moment of silence the night before the second anniversary of the start of the Syrian Revolution at the Citadel, an ancient Roman landmark in Amman.

Syria's devastating conflict entered its third year on Friday with EU leaders frustrated over the failure of diplomacy to end the bloodshed pressing to arm rebels despite Russian objections.

The Syrian Revolution 2011 Facebook page, a key driving force behind the uprising, has called on people to demonstrate after the main weekly Muslim prayers under the rallying cry “Two years of sacrifice towards victory”.

The conflict erupted on March 15, 2011 when protesters inspired by Arab world uprisings took to the streets of cities and towns across Syria for unprecedented demonstrations to demand democratic change.

Despite the demonstrators being unarmed, peaceful and made up of many women and children, forces of President Bashar al-Assad unleashed a brutal crackdown, opening fire on them and prompting an ever-growing number to take up arms.

Two years on, Syria is mired in a civil war that has killed at least 70 000 people and forced one million to flee abroad, with millions more missing or displaced inside the country, sparking an economic and humanitarian disaster.

Rebels have seized large swathes of territory, but growing tensions between liberals and moderate Muslims on the one hand, and Islamists on the other, have raised fears of a collapse into a sectarian bloodbath.

In power for more than 40 years, the Assad clan believed it could quell the revolt, just as Bashar's father and predecessor Hafez did in 1982, when he crushed a Muslim Brotherhood uprising in Hama, killing between 10 000 and 40 000 people.

The military has formidable firepower, and clashes with outgunned rebels have reduced many cities to rubble.

Britain and France have announced moves to begin addressing that imbalance by lifting an arms embargo on Syria, and the issue was expected to come up again on Friday on the second and final day of an EU summit in Brussels.

“Our goal is to convince our partners at the end of May, and if possible before.... If by chance there is a blockage by one or two countries, then France will take its responsibilities,” French President Francois Hollande said on Thursday.

“Political solutions have now failed, despite every pressure.

“We must go further because for two years there has been a clear willingness by Bashar al-Assad to use every means to hit at his own people,” Hollande added.

Syria's main opposition bloc, the National Coalition, welcomed France's initiative as “a step in the right direction”.

Assad's government, like its key foreign ally Russia, said any such arms shipments would be a “flagrant violation” of international law.

The United States may look favourably on the British and French moves to give more aid to the rebels, the State Department said, without explicitly backing arms shipments.

“We're obviously not going to get in the middle of their internal discussions, but we certainly want to see as many governments as possible provide appropriate support to the Syrian opposition coalition,” said State Department spokeswoman Victoria Nuland.

However, Berlin is known to be cool to the idea with German Chancellor Angela Merkel saying the EU needed to “proceed very cautiously” on lifting the embargo.

Violence across Syria killed 178 people on Thursday - 66 rebel fighters, 62 civilians and 50 government troops, said the Britain-based Syrian Observatory for Human Rights.

Twenty of the rebels and 22 of the soldiers died in third city Homs, a symbol of the resistance until the army laid siege to the rebel stronghold district of Baba Amr before overrunning it early in 2012.

The army on Friday resumed an assault on parts of Homs infiltrated by the insurgents, including Baba Amr, the Old City and Khalidyeh, said the Observatory, which bases its reports on a network of sources on the ground.

Troops also pounded south Damascus and clashed with rebels in the towns of Harasta and Irbin, northeast of the capital, as well as in and around second city Aleppo, in Syria's north. - AFP