Rami Nakhle, a spokesman in Beirut for the Local Coordination Committees in Syria, told the Los Angeles Times the protests are "more than usual."
"Because of the crackdown in Hama, people all over went out on the streets in solidarity," the opposition spokesman said. "This is what happens when the government tries to stop us."
A state news agency reported Thursday the opposition rejected President Bashar Assad's decree permitting opposition parties and dozens more civilians were reported killed by security forces.
Assad's decree grants citizens the right to establish political parties with the aim of contributing to political life "through peaceful and democratic means," the state-run Syrian Arab News Agency reported Thursday.
The embattled opposition movement dismissed the decree, alleging it was simply for show and would produce no real change.
The U.S. State Department called the announcement "empty rhetoric" while French Foreign Minister Alain Juppe scorned it as "almost a provocation," given the scale and duration of the repression.
The announcement of the law came as Syrian forces once again shelled Hama and plainclothes gunmen shot people in the streets in the fifth day of a tank, armored vehicle and sniper assault on the rebellious city, residents and activists said.
Footage on YouTube showed the bloodied corpses of four men said to have been killed by tank or cannon fire. Traditional news media are not allowed in much of Syria.
The city suffers from a critical food shortage, activists said.
Hama, a city of 700,000 north of Damascus whose name means "fortress," has emerged as a linchpin of the nearly five-month uprising.