The dozens of Iranians abducted by rebels in Syria included retired military officials visiting the violence-hit nation on a pilgrimage, the semi-official Iranian Students News Agency reported Wednesday.
The news agency attributed the information to Iranian foreign minister, Ali Akbar Salehi.
"The desire to visit holy places in Syria is so strong that we cannot stop the faithful from making these pilgrimages," Salehi said.
Pilgrims included some retired members of the elite Iranian Revolutionary Guards, he said, according to the news agency.
In a televised video, a group of Free Syrian Army rebels claimed responsibility for the kidnapping of 48 people, saying they are members of the Guards, not religious pilgrims as reported by Iranian media.
In a letter he sent to the United Nations on Tuesday asking for its help in freeing the people, Salehi cited reports saying three of the 48 captives were killed.
Iran, a staunch ally of Syria, also has asked Turkey to help secure the release of the captives because the latter has tense relations with the Syrian regime, but is sympathetic to the rebels.
As the international standoff continues, Syrian forces pounded some neighborhoods with heavy artillery Wednesday in the city of Aleppo, a rebel fighter said.
Random shelling hit two residential buildings in Sukari neighborhood, according to rebel fighter Abu Ayham in Aleppo, Syria's most populous city..
Nearby suburbs including Hnano and Shaar also sustained heavy shelling overnight, opposition activists said.
Regime forces and rebels have battled for control of the commercial hub for days, leaving a trail of destruction in a metropolis replete with historic buildings.
The international community remains at odds over a resolution, with Iran warning other nations to stop meddling.
Iran extolled its "axis of resistance" with Syria against other world powers as Saeed Jalili, a top Iranian official, met with Syrian President Bashar al-Assad in a display of solidarity.
During the meeting with al-Assad, Syrian state media quoted Jalili Tuesday as saying that Iran will not permit "enemies" to interfere in Syria. It was the first public video of the president since last month.
"What is taking place in Syria is not an internal issue, but rather a conflict between the resistance axis on one hand and the enemies of this axis in the region and the world on the other hand, with the goal being to strike Syria's resistant role," Jalili said, according to state media.
World powers have not intervened in Syria, but the lines in the sand have been drawn regionally and internationally.
Nations such as the United States, France, Britain and Turkey, as well as Arab League countries such as Qatar and Saudi Arabia, have supported Syrian rebels and the opposition.
Syria has been supported by Iran and groups such as Hezbollah, the Lebanese militant group.
The Iranian diplomat called on Syrians to forge a solution to the crisis, which morphed into a nationwide uprising and civil war after government forces cracked down on peaceful protesters in March 2011.
Roughly 17,000 people have been killed since the Syrian conflict began, the United Nations said last month. The opposition has put the toll at more than 20,000.
CNN's Salma Abdelaziz contributed to this report.