Another said: "Five tanks are now deployed outside the governor's palace," and spoke of intermittent gunfire, while a third resident reported seeing four BTR-type armoured personnel carriers.
Elsewhere, "six people were killed and 50 wounded by security forces in the eastern city of Deir Ezzor and three were killed and dozens wounded at Harak in the southern Deraa region," Abdel Rahman said.
The oil hub of Deir Ezzor and Hama have been rallying points for pro-democracy protests since mid-March, while Hama has a bloody past.
In 1982, an estimated 20,000 people were killed in Hama when the army put down an Islamist revolt against the rule of President Bashar al-Assad's late father, Hafez.
The president replaced the governor of Hama after a record 500,000 protesters rallied in the opposition bastion on July 1 calling for the fall of the regime.
Activists said at the time it was the single largest demonstration of its kind since the pro-democracy movement erupted on March 15.
Since security forces gunned down 48 protesters in the city on June 3, Hama has escaped the clutches of the regime, activists say. The next day, more than 100,000 mourners were reported to have taken part in their funerals.
On Saturday, Abdel Rahman said troops shot dead three people who stoned a military convoy heading to quell growing anti-regime dissent in Deir Ezzor.
He said about 60 military vehicles including tanks, personnel carriers and trucks crammed with soldiers deployed in the city.
"The troops opened fire to frighten residents after reaching the governor's office," he said, quoting witnesses.
There were mounting fears the army was preparing to crack down on Deir Ezzor, increasingly at the forefront of anti-regime protests.
A man identifying himself as a Syrian army colonel told AFP in Nicosia that he had defected and has "hundreds" of troops under his command ready to confront the regular army in Deir Ezzor.
Riad al-Asaad warned the authorities against carrying out any operation in Deir Ezzor.
"I warn the Syrian authorities that I will send my troops to fight with the (regular) army if they do not stop the operations in Deir Ezzor," Asaad said.
"I am the commander of the Syrian Free Army," he said, adding that he commanded "hundreds" of troops and was calling from inside Syria "near the Turkish border."
His claim could not be independently verified.
Deir Ezzor, the main oil- and gas-producing region in Syria, which produces 380,000 barrels of oil per day, has seen almost daily demonstrations against the regime.
Meanwhile an opposition figure who declined to be named told AFP that 15 conscripts broke ranks from the troops who entered the central city of Homs on Saturday and fled.
"They have sought protection with residents," the source said.
On Friday, at least three people were killed in Deir Ezzor when security forces opened fire on 300,000 mourners at the funerals of three people killed the previous day, according to activists.
A total of 20 people were killed and 35 wounded on Friday across Syria as hundreds of thousands of demonstrators held anti-regime protests, rights groups said.
Syrian opposition figures meeting in Algeria on Saturday spoke out against any foreign intervention as the bloody crackdown continued.
"We refuse all foreign intervention, we refuse to carry weapons," said Adnane el-Bouch, a Syrian lawyer living in Algeria, during a meeting of a Syrian support committee at Amnesty International premises.
"It's a peaceful revolution... our weapons are cameras and mobile phones."
Since anti-regime protests broke out, the crackdown on dissent has resulted in the deaths of more than 1,500 civilians and more than 360 members of the security forces, according to a Syrian Observatory toll.
More than 12,000 people are also reported to have been arrested in the crackdown, and thousands of others have fled the country, rights groups say.
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