Syrian President Bashar al-Assad poured troops into a suburb of the capital overnight while his tanks pounded Deraa to crush resistance in the southern city where the revolt against his autocratic rule began on March 18.
White buses brought in hundreds of soldiers in full combat gear into the northern Damascus suburb of Douma, a witness told Reuters on Wednesday, from where pro-democracy protesters have tried to march into center of the capital in the last two weeks but were met with bullets.
More than 2,000 security police deployed in Douma on Tuesday, manning checkpoints and checking identity cards to arrest pro-democracy sympathizers, said the witness, a former soldier who did not want to be identified.
He said he saw several trucks in the streets equipped with heavy machineguns and members of the plainclothes secret police carrying assault rifles. He believed the soldiers to be Republican Guards, among the units most loyal to Assad.
Diplomats said Assad sent the Fourth Mechanised Division, commanded by his brother Maher, into Deraa on Monday where demonstrations demanding political freedom and an end to corruption erupted more than a month ago.
Syria has been ruled by the Assad family since Bashar's father, the late President Hafez al-Assad, took power in a 1970 coup. The younger Assad kept intact the autocratic political system he inherited in 2000 while the family expanded its control over the country's struggling economy.
Assad has strengthened Syria's ties with Shi'ite Iran, both countries back the Hezbollah and Hamas militant groups, while Damascus still seeks peace with Israel. Syria and Israel are technically at war but the Golan frontier between them has been quiet since a 1974 ceasefire.
The 45-year old president had dismissed suggestions that the tide of the Arab revolutions could reach Syria, until pro-democracy protests erupted in Deraa on March 18.
Assad's attempts to appease discontent by lifting emergency law while keeping the draconian powers of the secret police and the ruling Baath Party's monopoly on power have not stopped the protests.
But Assad, a member of Syria's Alawite minority, still retains support, especially among co-religionists who dominate the army and secret police and could lose preferential treatment if majority Sunni Syria was to transform into a democracy.
An alliance between the ruling minority with the Sunni merchant class, forged by the elder Assad through a blend of coercion and the granting of privileges, still holds, robbing protesters financial backing and a foothold in the historic bazaars of Damascus and in Syria's second city Aleppo.