Syrian forces fired teargas to disperse a pro-democracy protest in Damascus on Friday and several thousand people in the southern city of Deraa called for the overthrow of President Bashar al-Assad, witnesses said.
Activists also reported demonstrations in the Damscus suburb of Douma and in the eastern towns of Deir al-Zor and Qamishli, despite Assad's decision on Thursday to lift emergency law, a central demand of the month-long protests.
A witness told Reuters by phone that security forces fired teargas from a flyover overlooking Midan, a district just outside the walls of Old Damascus.
"There were over 2,000 protesters and now hundreds have re-grouped," the witness said. Chants of "the people want the overthrow of the regime", the rallying cry of Arab uprisings from Tunisia to Yemen, were audible in the background.
More than 220 protesters have been killed since protests erupted on March 18 in Deraa, rights campaigners say, including 21 protesters killed this week in the central city of Homs.
Ahead of the main weekly prayers on Friday, which have often proved the launching pads for major demonstrations, the army deployed in Homs and police put up checkpoints across Damascus, apparently trying to prevent protests sweeping in from suburbs.
After prayers finished in Deraa, several thousand protesters gathered chanting anti-Assad slogans. "The Syrian people will not be subjugated. Go away doctor (Assad), we will trample on you and your slaughterous regime", they shouted.
A decree Assad signed on Thursday that lifted emergency law, imposed by his Baath Party when it took power in a coup 48 years ago, was seen by the opposition as largely symbolic, since other laws still give security forces wide powers.
In the first joint statement since protests erupted five weeks ago, activists coordinating the mass protests demanded on Friday the abolition of Baath Party monopoly on power and the establishment of a democratic political system.
"All prisoners of conscience must be freed. The existing security apparatus has to be dismantled and replaced by one with with specific jurisdiction and which operates according to law," they said in the statement, which was sent to Reuters.
Aided by his family and a pervasive security apparatus, Assad, 45, has absolute power in Syria.
"DAY OF RECKONING"
Joshua Landis, a Syria expert at Oklahoma University, said the Syrian government had "drawn a line in the sand" after offering concessions, and that Assad made clear he believed "there is no longer reason to demonstrate".
"The organisers of the revolution vowed to turn out their largest numbers yet ... They are determined to bring down the regime and understand that this is their chance," he said.
"Friday will be a day of reckoning".
A rights activist said on Thursday trucks carrying soldiers and vehicles equipped with machine guns were seen on the main highway from Damascus to Homs, a central city that has emerged as the new focal point of protests.
Soldiers in groups of five patrolled the streets of Homs on foot overnight. Plainclothes security police and others wearing camouflage uniforms were also present, two witnesses said.
A Damascus resident said police had set up checkpoints across the capital overnight, and security forces were also present at the city entrances, apparently to prevent protests sweeping into Damascus from the suburbs.
Another resident said army buses dropped security forces dressed in tracksuits on streets leading into Abbasside square.
Human Right Watch said Assad "has the opportunity to prove his intentions by allowing (Friday's) protests to proceed without violent repression.
"The reforms will only be meaningful if Syria's security services stop shooting, detaining, and torturing protesters," said Joe Stork, the group's deputy Middle East director.
Assad's conciliatory move to lift the state of emergency followed a familiar pattern since the unrest began a month ago: pledges of reform are made before Friday when demonstrations are the strongest, and are usually followed by an intense crackdown.
The authorities have blamed armed groups, infiltrators and Sunni Muslim militant organisations for provoking violence at demonstrations by firing on civilians and security forces.
Western and other Arab countries have mostly muted their criticism of the killings in Syria for fear of destabilising the country, which plays a strategic role in many of the conflicts in the Middle East.
Syria is technically at war with Israel but has kept its Golan Heights front with the Jewish state quiet since a 1974 ceasefire. It has long borders with Iraq, and supports the Palestinian Islamist group Hamas and the Shi'ite Hezbollah movement in neighbouring Lebanon, also backed by Iran.