Syrian students rallied in Damascus on Monday to express solidarity with protesters killed over the weekend, as the army moved in on the flashpoint town of Banias.
France and Germany, meanwhile, slammed the deadly assaults by security forces on anti-regime protesters and called on President Bashar al-Assad to make good on his promises of reform.
"Students rallied in solidarity with the victims of Daraa and Banias, chanting 'We will sacrifice our soul and blood for you martyrs'," a human rights activist told AFP.
He was referring to the southern town of Daraa, a protest hub where rights groups say 26 people were killed on Friday, and the northern coastal town of Banias, where a bloody weekend crackdown left four civilians dead, according to witnesses.
A YouTube video of the Damascus rally showed students chanting "Allah, Freedom and Syria, only!", a recurring slogan of anti-regime protests demanding political reforms and more freedom.
They also chanted "One, one one... the Syrian people are one!", in an apparent bid to exorcise the ghost of sectarian strife raised by authorities as the protests death toll rises.
Abdel-Karim Rihawi, president of the Syrian League for the Defence of Human Rights, told AFP some demonstrators chanted pro-regime slogans before security forces intervened and made arrests.
Political unrest erupted in Syria in mid-March, but anti-government demonstrations, challenging Assad to introduce major reforms, have been largely confined to the provinces.
Syrian troops surrounded Banias with up to 30 tanks on Monday as residents buried their dead and as electricity in the town was cut off, witnesses, activists and residents told AFP.
"The army is shooting sporadically to provoke people, but not a single demonstrator has fired," an activist said, adding that calls were made from minarets of the mosque urging the army to hold fire.
"Bashar al-Assad is sending us a message: punish those who dare demand freedom with death," a university professor told AFP by telephone.
Government forces on Sunday killed at least four civilians and wounded 17 when they strafed a residential area of Banias with gunfire for hours, witnesses said.
Nine soldiers, including two officers, were later killed and several wounded when their patrol was ambushed outside the town, the official SANA news agency said.
Anas al-Shuhri, one of the leaders of the protest movement, said three of the civilian casualties were "killed by sniper fire" and blamed "regime henchmen" for the violence.
He said they "had fired on the army to push them to respond" against peaceful demonstrators and accused them of "seeking to stir sectarian unrest."
Residents of Banias on Monday buried the four civilians killed over the weekend, Rihawi said.
He said there were several arrests in Banias overnight, including associates of former vice president Abdel-Halim Khaddam, a dissident living in exile in Paris since 2006.
Meanwhile, Syrian human rights organisations demanded an investigation into the Sunday clashes in Banias.
They called for the creation of a "neutral, transparent and independent investigative committee" in order to "sanction the perpetrators of the violence" which they wanted to end immediately.
Meanwhile, France on Monday condemned deadly assaults by Syrian security forces against anti-government protesters and urged Damascus not to resort to deadly force.
"Reform and repression are not compatible," a foreign ministry spokeswoman said.
Germany also slammed the "shocking" violence against peaceful demonstrators in Syria, and called on Damascus to stop "grave human rights violations" and hold perpetrators accountable.
Assad, a German government spokesman said, had repeatedly announced "political reforms and greater freedom," adding that "now would be a truly good time to turn those words into action."