The crackle of heavy-caliber gunfire erupts in the dawn skies over the city Dara, the flash point of the Syrian revolution -- now apparently under siege by its own government.

Syria's leaders have ordered tanks to crush a popular uprising in the southern city of Dara, say residents of the city that started the five-week old peaceful popular revolt against the regime of President Bashar Assad.

The video above is said to show soldiers and and a gunner on a tank firing into the city. Unlike Egypt and Tunisia, where the armies maintain a relatively neutral role, Syria's armed forces remain a bastion of loyalty to the minority Alawite community and Assad's clan.

According to activists quoted by Al Jazeera television, authorities have cut off phone service and disconnected electrical power to the farming hub, where the arrest and alleged torture of teenagers accused of writing graffiti sparked the weeks-long unrest now gripping Syria.

Witnesses told Al Jazeera that army officers and gunmen loyal to Assad have engaged in what they described as a bloody and indiscriminate crackdown on demonstrators. Agence France-Presse has reported that a military force of 3,000 men has marched into Dara.