Regime and rebel forces engaged in clashes in Syria's largest city today, breaking a cease-fire agreement only hours after it got underway.

United Nations special envoy to Syria Lakhdar Brahimi brokered the deal, timed to coincide with the Muslim holiday Eid al-Adha, in hopes that a temporary cessation of violence would provide a window for work to begin on negotiations.

Rebel forces said the Syrian Army attacked this morning, the first day of the four-day holiday, after rebels made advances in the city last night for the first time in weeks. The government had previously said it would hold to the cease-fire only if the rebels did; some rebel commanders said the same, while others refused to agree to any break in the fighting.

The Syrian Army intermittently shelled rebel forces and the two sides exchanged gunfire on multiple fronts in Aleppo today, where the government and the rebels have been locked in a fierce battle for Syria's manufacturing and industrial center since July. However, the light clashes were nothing like the intense battles that raged in the city weeks ago.

Not long after sunset, a large shell exploded over the city, leaving a plume of black smoke. In the neighborhood of Karm el-Jebel, the commander of the rebel brigade fighting in the area said regime forces began attacking in the morning, and shelled rebel positions with two tanks in the afternoon.

"There is no ceasefire," said Abu Yazem, commander of the rebels' Martyr Abu Abdu Brigade and a former Syrian Army officer who asked that his full name not be used. "From early this morning, they started to shoot at us."

He conferred with a small group of his fighters as darkness descended on the completely deserted neighborhood. No lights shown from the broken buildings, and the only sign of life was a family of stray cats that mewed loudly while scurrying through the rubble-strewn streets. The crack of gunshots echoed in the darkened neighborhood.

Abu Ali Saqr, the head of the Saqr el Quraysh brigade, said his men fought regime forces in Salaheddin area. "The ceasefire is fake," he says. "Last night a missile from the regime landed here," he said, gesturing to the roof of the building where a rebel division is headquartered.

The fighting today came after the rebels made gains in three areas of the city last night. Officers from the Liwa el Tawheed division said the rebels took the districts of Ashrafieh and Bani Zeid, both Kurdish areas, through a deal with the local armed Kurdish group, which has previously refused to join the revolution. The rebels and the armed Kurdish group are negotiating over the fate of missing rebel soldiers who disappeared after entering the Kurdish areas.

Get the Monitor Stories you care about delivered to your inbox. By signing up, you agree to our Privacy Policy

Though the rebels have made gains, the regime still has a firm hold on parts of the city.

In rebel-held parts of Aleppo earlier today, men waited with herds of sheep they hoped residents would buy for the holiday. Traditionally, families buy a sheep or another animal and slaughter it on the Eid, eating some of the meat and giving the rest to the poor. But customers were few and far between in the city. Many residents have fled the fighting, while others can no longer afford to buy a sheep or don't wish to celebrate. According to opposition estimates, more than 30,000 people have died since the uprising began in March 2011.