The opposition Local Coordination Committees said the barrage was steady, but with pauses every four minutes, CNN reported. The Syrian Network for Human Rights in London said 32 people were killed around the country Sunday, including a media photographer.
Fighting between President Bashar Assad's military and dissidents demanding his ouster has been going on for 15 months. Saturday, opposition groups said 96 civilians had been killed.
The government countered by saying 57 "army, law enforcement and civilian martyrs" had been buried.
Various international observers' estimates place the death toll at more than 10,000 since the rebellion began.
Meanwhile, the opposition Syrian National Council, recognized by most countries as a legitimate party, announced its new leader was a minority Kurd, Abdul Baset Sieda, who is living in exile in Sweden.
However, Assad refused to recognize the legitimacy of the party, repeating his vow Syrian leadership wouldn't be controlled by "foreign" interests.