New video has emerged of what appears to be security forces beating men in the Barzeh district of Damascus
Some of Syria's leading intellectuals have called for sweeping political change that could end 41 years of Assad family rule, at a rare conference allowed by the authorities under pressure from a three-month uprising.
Participants said Monday's meeting, held at a hotel in the centre of Damascus, was unprecedented in five decades of the Baath Party's monopoly of power.
Facing the biggest threat to his rule since he succeeded his father 11 years ago, Bashar al-Assad, the Syrian president, has held out the prospect of political reforms while sending his troops to crush protests across the country.
Many opposition figures have rejected Assad's call for dialogue as insufficient and some activists refused to take part in the conference, saying it could be exploited by authorities while mass killing and arrests continue.
Nevertheless, the conference included outspoken opponents of Assad, some of whom pulled no punches.
In-depth coverage of escalating violence across Syria
"We will talk so that we can formulate a national strategy on how to end Syria's current crisis," Abdel Karim Rihawi, president of the Syrian League for Human Rights, told AFP news agency, stressing that the meeting was not intended to take the place of the "protesters in the street".
Among the participants was Michel Kilo, one of Syria's most prominent writers and pro-democracy activists, who spent years as a political prisoner.
Another participant, writer and activist Loay Hussein, said Syrian authorities were informed of the meeting and had not blocked it. There would be no government representation, he said.
Meanwhile, Syria said on Monday it will hold talks with the opposition on July 10 to set the framework for a national dialogue.
The state news agency SANA said constitutional amendments, including changes to an article which puts the Baath Party at the centre of Syrian politics, would be on the agenda of the July 10 meeting.
'Cover-up for crackdown'
The opposition gathering was hailed by the government as an example of the promised reforms, but some activists dismissed it as a "publicity stunt" because of the absence of groups such as the banned Muslim Brotherhood.
Some critics also said the meeting was giving legitimacy to the regime while a crackdown on anti-government protesters continued.
"This meeting will be exploited as a cover-up for the arrests, brutal killings and torture that is taking place on a daily basis,'' opposition figure Walid al-Bunni, who was not participating in the conference, said.
Writer Loay Hussein speaks to Al Jazeera
Al-Bunni told The Associated Press news agency that he was not invited to the meeting because authorities had "vetoed" some names.
"We would have been happier if the organisers of the conference were free to invite whomever they wanted ... as it is, this is not an opposition conference,'' said.
A pro-Assad demonstration was held outside the hotel as the conference got under way.
Syria is essentially a one-party state, ruled by the Baath Party since 1963. Many government critics have spent years in prison.
Anti-government protests seeking to end the one-party rule have swept Syria since March, prompting the authorities to launch a crackdown.
However, in an address to the nation on June 20, the president proposed a "national dialogue" which he said could lead to a new constitution and even an end to the ruling party's absolute powers.
But Anwar al-Bunni, a prominent human rights lawyer who has spent five years in Syrian jails, told AFP that opponents would take part in the dialogue only if peaceful demonstrations were authorised, political prisoners released, the opposition recognised and the use of force ended.
The opposition says about 1,400 people have been killed - most of them unarmed protesters - in the continuing government crackdown.
Some of the dissidents who gathered in Damascus sought to distance themselves from opposition activists who met in the Turkish resort of Antalya earlier this month and who included members of the Muslim Brotherhood as well as secular politicians.
"We have no links with the opposition activists abroad - we too question their real objectives," writer Nabil Saleh said.