Syrian forces fired on thousands of protesters Friday in Aleppo, killing a teenager, after a raid on dormitories at the city's main university killed four students and enflamed tensions in a key bastion of support for the regime.

An Aleppo-based activist said the protests were the largest the city has seen since the start of the uprising against President Bashar Assad in March 2011. Aleppo is a major economic hub that has remained largely loyal to Assad over the course of the 14-month uprising.

"The people are incensed by what happened at the university," said the activist, Mohammed Saeed. "Everyone wants to express solidarity with those students."

Saeed said security forces were out in full force, firing live ammunition to disperse protesters and arresting people randomly.

"With our blood, we sacrifice for you students!" people shouted.

Although Aleppo has largely been spared widespread violence, anti-government protests have been on the rise. In recent weeks, university students _ many from rebellious areas such as the northern Idlib province _ have been staging almost daily demonstrations.

"This is what prompted this extremely brutal attack by the government ... this is proof that the regime has started to worry about Aleppo rising up," said Omar Idilbi, a member of the Syrian National Council opposition group.

During Friday's protests, security forces killed a 16-year-old youth in the Salaheddine district of Aleppo and wounded around 30 other people, Saeed said. Scores also were arrested, he said. The British-based Syrian Observatory for Human Rights, which relies on a network of activists on the ground in Syria, confirmed that a teenager was gunned down.

Amateur videos showed a large number of people shouting "Allahu akbar," or "God is great," as a protester climbed an electricity pole in Salaheddine to hang a flag that the opposition has adopted as its own _ the national flag that dates to before the ruling Baath party took over.

Other videos showed protesters shouting: "Death rather than humiliation!"

In the Damascus district of Kfar Souseh, regime forces opened fire Friday on hundreds of mourners during a funeral procession, forcing people to flee in panic as bullets whizzed overhead, said a witness who spoke on condition of anonymity for fear of reprisals.

The witness said she took cover under a tree in a backyard when she saw a sniper shoot a man in his 20s as he tried flee the shooting. She said she saw the bodies of three people killed by army gunfire.

The violence has further highlighted doubts over a peace plan brokered by international envoy Kofi Annan nearly a month ago.

A spokesman for Annan said Friday the international envoy believes his peace plan for Syrian remains "on track" _ a day after the Obama administration offered a far bleaker view, saying the plan might be doomed.

A U.N. team of up to 300 members is to monitor compliance with a truce. U.N. peacekeeping chief Herve Ladsous said about 40 U.N. observers are on the ground in Syria and that the force will grow to 65 by Sunday.

Joshua Landis, director of the University of Oklahoma's Center for Middle East Studies, said the protests in Aleppo could mark a shift in the conflict.

"University students are Syria's future. They are the youth of Syria's middle class and elite families _ the ones who are supposed to be sympathetic to the regime and leery of chaos and revolution," Landis said. Continued...