A Syrian opposition group said on Wednesday it would not attend a "national dialogue conference" suggested by President
Bashar al-Assad as other groups appear set to follow suit, DPA reported.
"Our group has sent a message to the Board of the National Dialogue, saying it will not attend the July 10 talks because the agenda of the conference does not recognise the source of the current crisis in the country, which is, in our view, disregard to the legitimate rights of citizens," said Luai Hussein, a member of the opposition Follow-Up Group.
The conference was called by al-Assad in an address in late June as part of promised reforms including a potential revamp of the constitution aimed at curbing unprecedented protests against his 11-year rule.
Hussein added on his page on the social networking website Facebook that the participants in the upcoming dialogue had no right to draft a new constitution "before opening the door wide for public freedom in Syria."
The boycott comes as the number of people killed in a crackdown launched by Syrian security forces in the central city of Hama has risen to 16, according to the opposition Local Coordination Committees.
The National Democratic Change, an umbrella opposition coalition of leftist parties and independent figures, has said it will meet on Wednesday to decide whether it will attend Sunday's dialogue.
Sources close to the group told the German Press Agency dpa that it would stay away from the dialogue due to what they described as "a lack of proper conditions."
In a report released on Tuesday, Amnesty International cited what it says are crimes against humanity committed by Syrian security forces during the county's violent crackdown on pro-democracy activists.
The London-based rights group urged the UN Security Council to refer Syrian forces to the International Criminal Court, impose an arms embargo and an asset freeze on al-Assad and his aides.