Drone lands on roof of Japan PM's office

A small drone covered with cardboard, is seen on the roof of Prime Minister Shizo Abe's official residence in Tokyo (Kyodo News via AP)

A police officer inspects a drone on the roof of Prime Minister Shinzo Abe's official residence in Tokyo REUTERS/Toru Hanai

Police and security officials stand around a tarpaulin covering a drone on the roof of Prime Minister Shinzo Abe's official residence in Tokyo REUTERS/Toru Hanai

Police officers inspect the roof of Prime Minister Shinzo Abe's official residence in Tokyo REUTERS/Toru Hanai

Police officer stands outside Prime Minister Shinzo Abe's official residence in Tokyo REUTERS/Thomas Peter

Officials carry a blue box that local media reported contains a drone from the rooftop of Prime Minister Shinzo Abe's official residence in Tokyo REUTERS/Thomas Peter

A small drone covered with cardboard, is seen on the roof of Prime Minister Shizo Abe's official residence in Tokyo (Kyodo News via AP)

A police officer inspects a drone on the roof of Prime Minister Shinzo Abe's official residence in Tokyo REUTERS/Toru Hanai

Police and security officials stand around a tarpaulin covering a drone on the roof of Prime Minister Shinzo Abe's official residence in Tokyo REUTERS/Toru Hanai

Police officers inspect the roof of Prime Minister Shinzo Abe's official residence in Tokyo REUTERS/Toru Hanai

Police and security officials stand around a tarpaulin covering a drone on the roof of Prime Minister Shinzo Abe's official residence in Tokyo REUTERS/Toru Hanai

Police officer stands outside Prime Minister Shinzo Abe's official residence in Tokyo REUTERS/Thomas Peter

Officials carry a blue box that local media reported contains a drone from the rooftop of Prime Minister Shinzo Abe's official residence in Tokyo REUTERS/Thomas Peter

A small drone covered with cardboard, is seen on the roof of Prime Minister Shizo Abe's official residence in Tokyo (Kyodo News via AP)

April 22 2015 08:02 AM

Japanese authorities are investigating after a drone landed on the roof of the prime minister's office.

No injuries or damage were reported. Premier Shinzo Abe was on a visit to Indonesia to attend the Asia-African conference when the small drone was discovered on the Tokyo building.

Police said it was not immediately known who was responsible. They are investigating the possibility it had crashed during a flight.

Public television NHK footages showed dozens of police and officials around the drone, which was covered by a blue tarpaulin.

NHK said the drone was about 50 centimetres (1.7ft) in diameter and had four propellers, carrying a small camera and something that looked like a flare. It was also decorated with a symbol that warns of radioactive material.

It was discovered by an official who was taking new employees on a tour of the prime minister's office in central Tokyo, according to reports.

Small drones are becoming increasingly popular in Japan and are often used for performances, aerial filming and other purposes. But they have raised safety and privacy concerns.

Japanese aviation laws have no restrictions for flying unmanned equipment at or below 820 feet above ground, except for flight routes.