A bomb has exploded near a government military building and a hotel used by a UN observer mission in central Damascus. This comes as the Organization of Islamic Cooperation is tipped to suspend Syria's membership.
Wednesday's bombing injured three near a government military building and a hotel used by United Nations monitors, Syrian state television reported.
The Opposition Local Coordination Committee confirmed the explosion, saying it occurred near a security building in the Ummayed square in Central Damascus.
State television reported the explosive was placed in a car parked behind the hotel, blowing up a fuel truck when it detonated.
Activists said the explosion echoed across much of the city. A video released by El-Ikhbariya, a Syrian pro-government television channel, showed fire-fighters extinguishing the blaze.
UN vehicles parked in the area were covered in ash and dust.
A video posted online by one opposition group, showed a vast plume of smoke and ambulances arriving at the scene to treat the wounded.
"There was a huge blast at first and then two small blasts followed," Haytham al-Abdallah, a Syrian activist in Damascus told news agency dpa.
"This is a highly secured area and also it is an area full of luxurious hotels, and where the headquarters of Syrian state television, and security and intelligence offices are located," al-Abdallah said.
Syria's deputy Foreign Minister, Faisal Mekdad, said none of the observers had been wounded in the blast.
"This is a criminal act aimed at distorting Syria's image," Syrian state television quoted the minister as saying.
The rebel Free Syrian Army claimed responsibility for the attack, according to Dubai-based broadcaster Al Arabiya.
The UN mission was not immediately available for comment.
A blast at a government security building in Damascus on July 18 killed four top security chiefs.
Air strike kills many, Assad rule 'collapsing'
Later on Wednesday, an air strike by the Syrian government on the northern town of Azaz caused widespread damage. An AFP correspondent at the scene said at least 10 houses were flattened in the town, a rebel stronghold used as a rear operating base just north of Aleppo, Syria's largest city and a major battleground in the conflict. AFP quoted Syrian Observatory for Human Rights director Rami Abdel Rahman as saying more than 20 people were killed in the air strike, including children.
In other developments, former Syrian Prime Minister Riad Hijab told a news conference in Amman that he thought President Bashar Assad now controls only 30 percent of Syria, less than a week after fleeing from his prime minister's post and heading to Jordan.
"The regime is collapsing, morally, economically, militarily," Hijab told reporters in the capital of Jordan. "I decided to leave on August 5, after losing hope that this corrupt and brutal regime would change."
"This action is being taken because Hijab is no longer a senior official of the Government of Syria," the US Treasury Department said in a statement.
Hijab, a Sunni Muslim, not an Alawite like the president, was not considered a part of Assad's inner circle, but rather a politician appointed in a bid to demonstrate inclusivity in the height of the 17-month Syrian conflict.
In Saudi Arabia, delegates from the 57-country Organization of Islamic Cooperation (OIC) are gathered to discuss a proposal to suspend Syria from the body as a result of the bloodshed. The move has the support of countries like Saudi Arabia, Turkey and Qatar, though Syria's main regional ally Iran is likely to oppose the move at the meeting in Mecca.
The smaller but more influential Arab League, with 22 member countries, suspended Syria's membership in November 2011 in response to the unrest.
Further fighting was reported across the country, but most notably in the flashpoint Aleppo on Tuesday.
Some activists groups estimate that 18,000 people have been killed in the conflict, though figures are difficult to verify and the UN has not issued an estimate since February.
The UN has reported that 150,000 refugees have registered in neighboring Turkey, Jordan, Lebanon and Iraq in the course of the conflict, with as many as 1.5 million feared to be internally displaced within Syria.
jlw, msh/mz (AFP, dpa, Reuters)