Thousands of people held an anti-regime protest on Friday under the banner of "Raqa the proud on the road to freedom" in solidarity with the embattled province of northern Syria.
The Syrian Observatory for Human Rights said the protesters were "greeted by bullets fired indiscriminately by the security forces" in the district of Mishlib and February 23 Street of Raqa city.
"One person was killed by regime forces during the demonstration and three others were killed by snipers in the same area shortly after, but we cannot confirm who was firing," Observatory director Rami Abdel Rahman told AFP by telephone.
Elsewhere in Syria, protesters vented their anger at Lebanon's Shiite movement Hezbollah, the international community and President Bashar al-Assad with chants, banners and caricatures.
In the Idlib town of Kfar Nabal, which has seen deadly air raids in the past week, demonstrators carried banners to denounce the escalating violence.
"World! Your carelessness produced extremists like Assad. Now, we need extremists to get rid of your products," read an English banner held by men and boys standing in front of a bombed-out building.
The message came a day after a spate of bombings across Damascus, including a suicide car bomb condemned by the regime and opposition, killed at least 83 people in the deadliest day for the capital since the March 2011 start of the Syrian conflict.
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In the town of Irbin, just northeast of Damascus, that has been the target of continuous bombardment by regime warplanes, a young boy stopped for a photo during a march to show his message to Assad: "We are coming to get you."
Meanwhile, the Facebook group "Lens of a Young Isqati" showed a demonstrator in the northwestern town of Isqat holding a cartoon of Hezbollah chief Hassan Nasrallah facing Israel and striking matches to light the fuse of a bomb.
But the fuse is facing the opposite direction and the matches land in Lebanon and Syria, where Hezbollah fighters were reported to have attacked opposition-held towns and villages from across the border last week.
Despite the ever-rising brutality of the conflict, which has left an estimated 70,000 people killed, demonstrations continue to be held every Friday nationwide.
In the Turkish border town of Ain al-Arab, demonstrators, including young girls and dancing teenagers, shouted for freedom as they held aloft Kurdish flags alongside the Syrian revolution banner in a video posted on YouTube.
At the Zaatari camp in northern Jordan for Syrian refugees, some 300 demonstrators rallied to urge the international community to arm the rebel Free Syrian Army, an AFP journalist said.
"Oh world, we want arms ... The people demand the arming of the Free Army," they chanted.