On Sunday, security forces tried to crush protests against President Bashar Assad's regime. The government raids left at least 70 people dead, 55 of them from Hama.
Less than 24 hours later, troops backed by tanks renewed their attempt to subdue Hama, a center of the revolt against the Assad family's rule.
Hama-based activist Omar Hamawi said tanks opened fire early Monday morning after a night of sporadic shooting.
The escalating government crackdown appears aimed at preventing the protests from swelling during the Muslim holy month of Ramadan, which began Monday.
More than 1,600 civilians have been killed in the crackdown on the largely peaceful protests against Assad's regime since the uprising began in mid-March.
Due to the events in Syria, the European Union is expanding its sanctions against that country.
The Associated Press contributed to this report.