In the central region of Homs, another hotbed of dissent, two civilians were killed, one shot by sniper fire, said a statement from the watchdog.
Further north, in Hama, five civilians, including a 12-year-old boy, were killed by heavy machinegun fire as the army and gunmen believed to be deserters clashes, the Observatory said.
The Local Coordination Committees, an activist network spurring protests on the ground, said security forces entered several towns to the east of Damascus looking for people "on the basis of lists."
State television, meanwhile, broadcast images of a huge pro-Assad rally in the coastal city of Latakia, saying that showed people's support for (Assad's) reform programme and their rejection of foreign interference.
On the diplomatic front, Foreign Minister Walid Muallem held talks with China's special envoy for the Middle East, who reaffirmed his country's opposition to foreign interference in Syria, Syria's official news agency said.
Muallem and Wu Sike met in Damascus and spoke of "the relations of solid friendship" between their countries, the agency said.
The Syrian minister explained "the current situation, measures taken by Syrian leaders to respond to the legitimate demands of its citizens and efforts made to implement reforms."
Wu called for an "end to all acts of violence and the spilling of both and to carry out reforms on the basis of dialogue and peaceful means.
"We hope that the Syrian government will accelerate efforts to carry out its promised reforms and launch an overall political process with the participation of a wide range of concerned parties, and as soon as possible, to respond to the aspirations and legitimate demands of the Syrian people."
Wu also reaffirmed the "pursuit of cooperation between the two countries within international bodies" as well as China's "opposition to attempts to interfere in Syrian affairs."
Several times since protests broke out in March, Assad has promised reforms, but opponents have said that these were too little too late.
Meanwhile, in a region bordering northern Lebanon, Syrian troops were seen planting mines in the early morning in an apparent bid to stop weapons smuggling along the porous border, a local Lebanese official told AFP.
He said the troops began planting the mines at dawn in an area facing two Lebanese villages -- Knaysseh and Al-Hnayder.
"A number of Syrian soldiers were also seen deploying on their side of the border, near the Syrian villages of Heet and Buwayt," he said, speaking on condition of anonymity.
The area is separated only by mounds of earth and for long has been used to smuggle goods between the two countries.
On October 4, permanent UN Security council members Russia and China vetoed a Western-proposed resolution threatening the Syrian leadership with "targeted measures" unless it halted the bloody repression.
The regime's brutal crackdown on protest has killed at least 3,000 people since mid-March, according to UN figures.
Pro-democracy activists, meanwhile, called for rallies on Friday to impose "a no fly zone" over Syria in order to protect civilians from military action and to encourage soldiers to defect.
"We call on the international community to impose a no fly zone so that the Syrian Free Army can function with greater freedom," said the Syrian Revolution 2011 on its Facebook page.
An army officer who has taken refuge in Turkey, Colonel Riad al-Asaad, claimed in July to have established an opposition armed force called the "Syrian Free Army", but its strength and numbers are unknown.