Three Iranian men being held captive by Syrian rebels have been killed during an air strike on the capital Damascus, according to activists.
The men were part of a group of 48 Iranians kidnapped on Saturday between the airport and the city.
Rebels accuse Iran of sending fighters from its Revolutionary Guard to help the Syrian regime to crackdown on a 17-month old uprising. Tehran says the men are pilgrims.
Syrian rebels have threatened to kill the remaining captives unless government forces stops their attacks.
Several groups of Iranians have been abducted in Syria since the uprising began in March 2011. Most have been freed.
The deaths come as Iran plans a regional meeting to help decide ways to resolve the Syrian crisis.