At least 47 people, including civilians, were killed Sunday in a twin attack in a mainly Shiite area in the Syrian capital Damascus, a monitoring group reported.
The attack occurred in the district of al-Sayeda Zainab in southern Damascus, the Syrian Observatory for Human Rights said.
A car bomb went off near a security checkpoint in the area, followed by an explosion caused by a suicide bomber blowing himself up in the crowd.
The dead included 16 pro-regime insurgents, according to the Observatory that relies on a network of activists inside Syria.
Syria's state news agency SANA said at least 45 poeple - all of them civilians - were killed in the attack.
No one has claimed responsibility for the bombing.
The radical Sunni Islamic State, which rules areas in war-torn Syria, previously took credit for similar attacks.
Sunday's attack comes as representatives from the Syrian government and the opposition are gathering in Geneva for indirect UN-sponsored attacks aimed at reaching a political soolution to the country's civil war.
A team from Syria's main opposition group is expected later on Sunday to meet with UN envoy Staffan de Mistura in Geneva.
The opposition said that it wanted to discuss purely humanitarian issues, such as lifting sieges and ending bombardment of civilian areas, before engaging in any political negotiations.
World powers hope the Geneva negotiations will initiate a political process to resolve the Syrian conflict, which is estimated to have killed more than 250,000 since it started in 2011.
The conflict has also driven more than 11 million people from their homes, according to UN estimates.