Syria unrest: Protests in Deraa, Damascus and Hama
Gunfire has been heard during a fresh protest march in the Syrian city of Deraa, reports say.
The marchers had attended funerals for some of the 25 protesters shot dead on Wednesday by security forces.
Demonstrations were also reported in the capital, Damascus, where there were some arrests, and in the towns of Hama and Tall.
Opposition activists had called for nationwide protests after Friday prayers, following a week of unrest.
The city of Deraa, south of Damascus, has become the centre of a serious challenge to the regime of President Bashar al-Assad.
Some of the protesters started a fire under a bronze statue of his father, the late President Hafez al-Assad, witnesses reported.
More than 40 people are thought to have been killed in the town in a week of protests, although it has been hard to verify the accounts.
Unconfirmed reports on Friday said another group of protesters trying to reach Deraa were killed in a nearby village when security forces opened fire.
A human rights activist told AFP news agency the deaths occured in Salamen village. A witness told al-Jazeera television channel at least 20 had died.
In Damascus, hundreds marched on King Faisal Street chanting: "Peaceful, Peaceful, God, Syria, Freedom".
This protest was broken up by security forces and many were arrested, reports say.
Another protest reported to the BBC by an eyewitness took place around al-Rifai near Qasar Sousah Square.
Supporters of Mr Assad were also staging protests in the capital, and clashes erupted between the two sides.
In Hama, hundreds of people were said to have gathered on the city streets to chant "freedom".
In 1982, the Syrian army put down an uprising led by the Muslim Brotherhood in Hama. Rights groups believe that tens of thousands of civilians were killed when large parts of the city were destroyed in the military assault.
In Tall, witnesses quoted by the Reuters news agency said about 1,000 people had rallied to show their support for the Deraa protesters, and were chanting slogans denouncing members of the ruling Assad family.
Changes promisedOn Thursday, the Syrian government said it would consider political reforms, including the possible ending of emergency laws introduced in 1963.
The government also said it would put on trial those suspected of killing several protesters in Deraa.
Mr Assad later ordered the release of everyone arrested during the "recent events", state media said.
Presidential spokeswoman Bouthaina Shaaban blamed outside agitators for whipping up trouble, and denied that the government had ordered security forces to open fire on protesters.
But she said this "did not mean mistakes had not been made".