The Syrian Observatory for Human Rights said regime forces were also shelling the central flashpoint city of Homs, which according to rights watchdogs has been under a relentless assault that has killed nearly 400 people since February 4.
"The neighbourhood of Baba Amr is once again being shelled this morning," the Britain-based group said in a statement.
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"The shelling also targeted the neighbourhoods of Inshaat and Khaldiyeh," it added.
In Daraa, cradle of the 11-month revolt against the regime of President Bashar al-Assad, the Observatory said a civilian was killed in clashes between security forces and defectors.
Three security force members were also killed.
In Damascus, security forces deployed in Qabun, on the northeastern outskirts of the capital, and were conducting search operations, the Observatory said.
Security forces were also searching homes and carrying out arrests in the town of Jasem, in Daraa province.
"Six people from the al-Halqi family have been arrested," said the monitoring group.
The Arabic-language daily Al-Watan said Thursday that security forces had managed to track down armed groups in Baba Amr and in orchards in Jobar and Sultaniyeh, also in Homs.
It said troops had "killed, injured and arrested several people" during these operations and had destroyed tunnels in the city that facilitated the movement of armed groups.
