The ScanEagle drone was gathering information over Gulf waters and had entered Iranian airspace when it was captured by the naval unit of the Revolutionary Guards force, the Fars news agency reported, without giving details.

Last month the US said Iranian warplanes shot at a US surveillance drone flying in international airspace. Iran said the aircraft had entered its airspace.

The ScanEagle is manufactured by Boeing Co. According to the firm's website, the drone is four feet long and has a 10-foot (three-metre) wingspan.