TEHRAN: Forty-eight Iranians held hostage by rebels in Syria and threatened with execution were in "good health," Iran's Foreign Minister Ali Akbar Salehi said on Wednesday.

"Thanks to God, all of them are in good health," Salehi said, according to the official IRNA news agency.

He said that Iran was in touch with Qatar and Turkey, supporters of the Syrian rebellion against the regime of President Bashar al-Assad, as well as the government in Damascus to secure the release of its citizens.

The Syrian opposition charges that Assad's regime is receiving support from its close ally Iran.

Syrian rebels on Monday postponed a threat to execute the Iranians held hostage since August, a Free Syrian Army (FSA) spokesman told AFP.

"Contact has been established with the Turkish authorities as part of indirect negotiations between the FSA and the Syrian and Iranian regimes," said Ahmed al-Khatib, spokesman for the FSA's Military Council in Damascus province.

"If the Syrian regime does not in the coming hours release three girls and two families detained from the Eastern Ghuta area of Damascus province, the group holding the hostages may start fulfilling their ultimatum," Khatib said.

On Thursday, the council said it would execute the hostages within 48 hours if the army did not withdraw completely from the Eastern Ghuta area, a focus of heavy military operations since early on in the anti-regime revolt.

The rebels claim the hostages are members of Iran's elite Revolutionary Guards.

Iran maintains the men were visiting Syria as pilgrims to a Shiite Muslim shrine in southeastern Damascus, but have also said some of them are "retired" members of the army and the Revolutionary Guards.

It has denied they were on active service in Syria.