Preliminary information indicated the bomber detonated his explosives at a traffic light in a heavily populated area of the Midan district, the Syrian Arab News Agency said.
The district recently has been the scene of protests against President Bashar Assad's government.
Arab League monitors are in Syria trying to ensure the government's compliance with a peace plan, but opposition activists and human rights organizations said a violent crackdown against anti-government protesters was still going on and dozens of people have died.
At least 24 people were killed Thursday, half of those in the northeastern Deir Ezzor province, the Local Coordination Committees activist group said.
Foreign news agencies cannot independently verify accounts from Syria because the government has restricted access.
A senior Syrian official who defected said the Assad regime redirected funds to security forces responsible for the brutal response to protesters.
Mahmoud Souleiman Hajj Hamad, head auditor at the Syrian defense ministry, told reporters in Cairo that in the course of his duties he determined the Assad regime reallocated money to security forces responsible for the violent 10-month crackdown against protesters.
"We were analyzing and seeing for ourselves that the regime's story about armed gangs going out and killing protesters was all lies," he told al-Jazeera Thursday. "I confirm there are no armed gangs -- they are all unarmed protesters."
Hamad said Assad's government spent about $40 million on loyalist militias and "paid thugs" to crush demonstrations since March as security forces besieged protests hubs across the nation.
"We saw them preparing and heading out in their armored vehicles and buses toward the young protesters and killing them," he told the TV network. "It has been happening since the beginning of the protests."
He also told CNN, "What is more horrific is the intelligence vans marked with the Syrian Red Crescent insignia that would drive through the protests as ambulances and start firing at protesters."
He said he blamed the carnage on the regime's intelligence service and the "thugs" he says were recruited for $100 a day plus accommodations to battle protesters.
"Bashar Assad is no longer able to control these human monsters," Hamad said. "We have reached a phase of genocide, and this can't be tolerated under any circumstances."
Hamad -- who said he and his family defected to Egypt by pretending they needed to register their son for college -- said most Syrian officials and government employees want to defect but are afraid of the consequences.
"Syrian government officials live in a kind of prison," he told al-Jazeera. "No one can go anywhere without being accompanied by a member of the security services."
Hamad said he had seen proof Iran and Iraq were aiding the Assad crackdown.
"The Syrian regime receives financial support from Iraq and Iran," he said.