Activists said six people had been killed in the city. On Friday, they reported at least 66 protester deaths in Syria, most of them in Deraa.
Officials said the number of dead was far lower, and included four soldiers.
State television said security forces had come under attack by "armed terrorists" in Deraa and Homs, Syria's third city.
In other developments on Saturday:
- Activists said 138 members of the ruling Baath Party in the southern Hawran region, in which Deraa is located, resigned on Saturday in protest against the crackdown
- Security forces reportedly arrested two veteran opposition figures - Hassan Abdul Azim, 81, was detained in Damascus, while 85-year-old Omar Qashash was arrested in Aleppo, according to the Syrian Centre for the Defence of Prisoners of Conscious
- Eleven women were arrested in the al-Salihiya district of Damascus after they took part in a silent all-female demonstration in support of the residents of Deraa, activists said
- UK Foreign Secretary William Hague voiced alarm at the reports of hundreds of deaths, saying: "The Syrian government has failed to heed repeated calls by the international community for restraint."
End Quote Abu Ahmed Deraa residentIt looks like [the security forces] want to finish their campaign today”
Earlier, another resident, Abu Ahmed, said: "It looks like [the security forces] want to finish their campaign today. From the new tank deployments, it looks as though they are intensifying their operations."
The Omari mosque has been a focus of the protests in Deraa since mid-March. Continued