TOKYO: The air traffic control system mainly covering eastern Japan temporarily suffered a glitch on Friday, triggering restrictions on departures of aircraft that fly over the area.

The system failure occurred at the Tokyo Area Control Center in Tokorozawa, Saitama Prefecture, north of Tokyo, at around 11:40 a.m., the transport ministry said.

Due to the glitch, the location information and flight numbers of aircraft were not displayed on the radar screen, the ministry said.

The restrictions were in place for about 40 minutes until around 12:20 p.m., causing delays in flights between eastern Japan and elsewhere in the country, the ministry said.

The ministry said it is looking into what caused the problem.

JIJI Press