Protesters flooded into the streets after Friday prayers in at least nine major cities across the country.

The demonstrations are a sign that President Bashar Assad's attempts to quell the month-long protests with a deadly crackdown and promises of reform have all but failed.

Ammar Qurabi, head of Syria's National Organization for Human Rights, said the death toll had reached 49. He said at least 20 people were missing.

"Bullets started flying over our heads like heavy rain," said one witness in Izraa, a southern village in Deraa province, the same region where the uprising kicked off in mid-March.

The protest movement has been the gravest challenge against the autocratic regime led by Assad, who inherited power from his father 11 years ago. The uprising in Syria takes its inspiration from the popular revolts sweeping the Arab world. But there are significant differences in Syria that make the protest movement there all the more unpredictable.

The country's military structure is one key difference — unlike the armies of Tunisia and Egypt, Syria's military and security apparatus will almost certainly stand by Assad, at least for the time being. That means there could be darker days ahead as the uprising gains momentum, something that has implications far beyond Syria's borders. Damascus stands in the middle of the most combustible conflicts in the region because of its web of allegiances, from Lebanon's Hezbollah and Gulf powerhouse Iran.

On Friday, tens of thousands of people protested in the Damascus suburb of Douma, the central cities of Hama and Homs, Latakia and Banias on the coast, the northern cities of Raqqa and Idlib, the northeastern Kurdish region and the southern province of Deraa.

As the protesters dispersed, the scope of the bloodshed began to emerge.

Outside the capital, witnesses said they saw at least five corpses at Hamdan Hospital. All suffered gunshot wounds.

In Deraa, other witnesses said at least 10 people were killed when protesters marched in front of the mayor's office in Izraa. They said an 11-year-old boy was among the dead.

A video posted on the protest movement's main Facebook page showed a man carrying a bloodied boy near a building as another child could be heard weeping and shouting "My brother!"

Qurabi said the fatalities occurred mostly in Hajar Aswad near Damascus and in the central city of Homs.

The protest movement has crossed a significant threshold in recent days, with increasing numbers now seeking the downfall of the regime, not just reforms. The security crackdown has only emboldened protesters, who are enraged over the deaths of more than 200 people over five weeks.