Security measures have reached new heights in Tokyo, with the city's police launching a fleet of interceptor drones with nets to catch 'suspicious' drones flying over sensitive locations.

The move by the Tokyo Metropolitan Police Department is a response to concerns for the Japanese prime minister's safety, Britain's The Telegraph reports.

It says a drone carrying trace amounts of radioactive caesium was intercepted on the top of Prime Minister Shinzo Abe's office last April, raising terror concerns in the Japanese capital.

Riot police will control the interceptor drones, which are equipped with cameras, to chase private drones they believe may be spying on buildings, including Mr Abe's office.

They'll snare the suspicious drones in large nets before landing.

Video of what might be seen as "the war or the drones" shows a police drone with a large net dangling from it, chasing another drone and scooping it into the net.