Syrian army troops on Saturday stormed the coastal city of Latakia in the latest crackdown on restive areas in the country, opposition activists said.
The broadcaster Al Jazeera quoted a member of the Federation of Coordination Committees of the Syrian Revolution, an opposition group, as saying that army tanks were deployed to Latakia's southern entrance, DPA reported.
He reported heavy shelling in some neighbourhoods of the city, which was the scene of overnight anti-government protests.
Twenty-three people were killed Friday by security forces during pro-democracy demonstrations held in several areas of Syria, according to the Federation of Coordination Committees of the Syrian Revolution.
The government of President Bashar al-Assad has stepped up its deadly clampdown on protests despite mounting international condemnation.
US Secretary of State Hillary Rodham Clinton on Friday called on countries still doing business with Syria to cut ties with Damascus and "get on the right side of history."
"We urge those countries still buying Syrian oil and gas, those countries still sending Assad weapons, those countries whose political and economic support give him comfort in his brutality, to get on the right side of history," she said in Washington.
"President Assad has lost the legitimacy to lead, and it is clear that Syria would be better off without him," she added.
Around 1,770 civilians and 410 security personnel have been killed since protests began in Syria in mid-March, the London-based Syrian Observatory for Human Rights said.
It is hard to verify these reports, as the Syrian authorities have barred most foreign media and international human rights groups from entering the country.