Radio interference Tuesday morning temporarily disrupted a channel used by air traffic controllers at Tokyo's Haneda airport, transport ministry officials said.
The incident comes after two other interference problems involving the airport and its air navigation facilities were reported last week.
Tuesday's interference occurred at around 10:18 a.m., but there was no disruption in airport communications as the air traffic controllers switched to another channel, the officials at the Land, Infrastructure and Transport Ministry said.
The Internal Affairs and Communications Ministry said the interference came from Yokosuka, Kanagawa Prefecture. It disappeared after about 40 minutes and the traffic controllers went back to the channel at 11:17 a.m.
The transport ministry has asked the Defense Agency and U.S. Forces in Japan to investigate the incident.
The disrupted channel is used to give instructions to pilots of departing planes.
The ministry said it cannot rule out the possibility the interference was a prank as the channel's frequency is similar to that used by amateur radio operators.
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