Surveillance balloons: This balloon serves as a watchful eye in the sky during the Tokyo Olympics.
The attached surveillance camera monitors activities on the ground.
This is a first for Japanese police patrolling. Multiple balloons monitor several venues from about 100 meters(328 feet) in the air.
Areas under scrutiny include the Olympic venues for skateboarding and tennis.
Police started using the balloons on July 6 to watch for accidents, traffic jams, and terrorist activity.
They will be operating until September 6, a day after the Paralympics end. Similar balloons were also deployed during the 2016 Rio Olympics.