Snipers in Damascus. Soldiers shooting protesters. Clashes outside a military camp.

The allegations of violence by the Syrian opposition came just hours after a temporary cease-fire was to have taken hold on Friday, dimming hopes that the killings that have wracked Syria would stop.

Video on YouTube purportedly shows men walking down a street in Damascus carrying guns. Constant gunfire can be heard as well as a man repeatedly saying “Allahu Akbar,” or God is great.

CNN is unable to authenticate the footage.

The idea of a cease-fire was met immediately with skepticism after it was floated on Wednesday. Diplomats, experts in the region and rebels fighting Syrian forces believed a truce that U.N.-Arab League envoy Lakhdar Brahimi tried to negotiate would fail. They said it would just be a repeated of a cease-fire declaration in April that failed without hours of its start.

On Friday, Brahimi’s temporary truce appeared doomed.

Thousands of people poured into the streets across Syria, using the start of the four-day truce that coincides with the revered Muslim holiday of Eid al-Adha as an opportunity to protest against President Bashar al-Assad.

The four-day religious holiday of Eid al-Adha begins at the height of the Hajj — the pilgrimage to Mecca in Saudi Arabia that annually draws 2 million Muslims. It is a time where Muslims gather with family and friends.

But within hours, reports of violence began to emerge, according to the opposition:

— At least 30 people were killed across Syria on Friday after the cease-fire was to be in place

— At least three people were killed in tank and sniper fire in a Damascus suburb where government forces have been battling rebel forces on-and-off for control.

— Fierce fighting broke out between government forces and the al Qaeda-linked al Nusra Front, which said earlier it would not abide by the terms of the temporary truce.

The al Nusra fighters laid siege to military encampment east of the city of Maaret al-Numan.

— Government forces shelled a neighborhood in the flashpoint city of Homs where the opposition alleged six rockets fell, wounding two people and damaging a number of buildings. Video of the alleged destruction appeared on YouTube.

— At least three people sustained gunshot wounds when Syrian forces fired shots in the air in an attempt to disperse protesters in the town of Inkhil in Dara province.

CNN can’t confirm reports of violence as the Syrian government has severely restricted the access of international journalists.

The negotiated truce is the latest international effort to end the bloodshed in Syria where some 32,000 people, according to the opposition, have been killed in fighting that began in March 2011.

Here are the key developments:

The terms of Syria’s agreement have raised skepticism among some observers: Damascus reserves the right to respond to “terrorist” attacks, including bombings, as well as “terrorists” trying to reinforce their positions; and to protect neighboring borders crossed by “terrorists.”

On the rebel side, a top Free Syrian Army general said Thursday his fighters had agreed to halt military operations if the Syrian government were to do so as well. But he said he doubted that the truce would hold.

Syria’s rebel opposition is fractured, and Gen. Mustafa al-Sheikh said that some rebel groups have not agreed to halt operations.

The government, meanwhile, touted its several goodwill efforts Thursday leading to its announcement that it will stop fighting.

State-run TV aired footage of men walking out of a prison — part of a government amnesty program, a commentator said.

The release comes a week after rebel fighters told Al Jazeera news agency that they would agree to a proposed cease-fire only if the government were to release detainees, end a siege in the city of Homs and halt aerial attacks.

‘Foolish to expect total cease-fire’

It’s foolish to expect a total cease-fire, said Aram Nerguizian, a Middle East expert at the Center for Strategic and International Studies in Washington.

A cease-fire in this context is about a larger goal of getting most rebel brigades and al-Assad forces to halt or reduce the killing.

— CNN’s Chelsea J. Carter contributed to this report.