India, Aug. 8 -- An unusual military aircraft has been making repeated flights over California and Arizona in recent weeks, puzzling spectators on the ground and sparking speculations from observers.

According to Flightradar24 records, the plane - an Airbus A400M Atlas operated by the United Kingdom's Royal Air Force - has been flying out of Oceanside, Blythe and Yuma airports for several days. Witnesses in Morro Bay reported seeing it flying low over the coastline, while others in Cupertino claimed it passed overhead at an unusually low altitude, remarking on its unusual appearance and massive size.

The Airbus A400M Atlas is a four-engine military airlifter specifically built for strategic and tactical missions. It can carry heavy-duty...