Seven Iranian military personnel were killed in Sunday's air strike on a Syrian air base, the private Tasnim news agency said, almost double the number originally reported.
Syria's government and its ally Iran have accused Israel of carrying out the attack on the Tiyas, or T-4, air base near Homs—something that Israel has not confirmed or denied. The bodies of the Iranians, described as military advisers, had been flown back to Iran and funerals would take place later on Tuesday, Tasnim said. Earlier Iranian media reports said four personnel were killed.
The Syrian Observatory for Human Rights, a British-based monitor, said at least 14 people were killed in the raid, some with foreign nationalities.
The semi-official Fars news agency named four Iranian "military advisers" it was were killed, with one of them Mehdi Dehqan Yazdeli, reported to be a member of the Revolutionary Guards Aerospace Force, a division that operates drones.
The attack took place hours after US President Donald Trump warned there would be a "big price to pay" following the reports of a poison gas attack on the Syrian rebel-held town of Douma. Syria's government has denied any involvement in that attack.
"It seems the US government is looking for an excuse for military intervention," Iran's foreign minister, Mohammad Javad Zarif, said has he arrived in Brazil early on Tuesday, according to state media.
"Iran's stance on chemical weapons is clear and we condemn any use of them against any target," Zarif added.
The Revolutionary Guards, Iran's most powerful military force, have been fighting in support of Syrian President Bashar Assad for several years. More than 1,000 Iranians have been killed in Syria's civil war, including senior members of the Guards.