DAMASCUS - A blast rocked the headquarters of Syrian state television in the heart of Damascus on Monday causing casualties, the broadcaster reported.
"An explosion hit the third floor of the Syrian television headquarters, causing casualties," it said.
Meanwhile, Iran "strongly" denies that 48 of its citizens taken hostage in Syria at the weekend are Revolutionary Guards, as claimed by their rebel captors, according to the state television website on Monday.
"We strongly reject the claims of some media that the kidnapped pilgrims are members of Iran's Revolutionary Guards," Amir Abdollahian, a deputy foreign minister in charge of Arab affairs, was quoted by the IRIB broadcaster as telling Iran's Al-Alam Arabic-language network.
"All of them are pilgrims who wanted to go to religious sites," he said.
Syrian rebels on Sunday posted an online video of 48 Iranians kidnapped the day before in Damascus, and charged they included members of Iran's elite Revolutionary Guards.
A man dressed in the uniform of Syria's rebel Free Syrian Army said in the video that the 48 "were on a reconnaissance mission in Damascus" when they were captured as they were travelling in a bus.
Abdollahian was quoted as saying: "Those who carried out this operation had pre-planned it. They had in the past kidnapped Iranian nationals. Their goal is to put pressure on Iran to halt its support for the Syrian nation."
Iran has appealed to Qatar and Turkey -- both governments with close relations with the Syrian opposition -- for help in securing the release of the hostages.
It says the Iranians were visiting the Sayyida Zeinab shrine, a Shiite pilgrimage site in the southeastern suburbs of Damascus that, before Syria's conflict, attracted hundreds of thousands Iranian visitors.
Tehran has repeatedly denied it has sent any military units to Syria, its key ally.
Iranian Defence Minister Ahmad Vahidi said on Saturday before the latest abduction was made public that "Iran has no armed forces in Syria and the Syrian government has not made such a request."