London, Oct 21 : Iranian security forces have arrested two pigeons for apparently spying near its Natanz nuclear facility.

According to the Etemad Melli newspaper, one of the pigeons captured near rose water production plant in the city of Kashan in Isfahan province had metal rings and "invisible" strings attached to it.

It is believed that the bird might have been communicating what it had seen with the equipment it was carrying.

"Early this month, a black pigeon was caught bearing a blue-coated metal ring, with invisible strings," the Telegraph quoted a source, as saying.

Last year, Iran issued a formal protest over the use of espionage by the United States to produce a key intelligence report on the country''s controversial nuclear programme.

It is also highly suspicious of Israel, whose extensive intelligence activities are not known to include the use of pigeons. (ANI)