Fighter planes from Iran have arrived in Iraq to provide air support for Iraq's fight against Sunni militants who have overtaken much of the country.
After Russia supplied Su-25 jets and the United States provided helicopters, drones and missiles, three Su-25s from Iran have arrived as well, said the International Institute for Strategic Studies, based in London.
IISS analysts said serial numbers on the Russian-built aircraft from Iran, seen on a video produced by the Iraqi Ministry of Defense, correspond with numbers known to be part of the Iranian regime's air force.
IISS suggested the planes are being flown by non-Iraqi pilots, noting Iraq has not used this type of aircraft since the first Gulf War.
Interview with former Iranian political prisoner Mostafa Naderi