OSAKA - Sixty-four thrill-seekers at Universal Studios Japan had what probably was their scariest roller-coaster ride on Tuesday (May 1) when their carriages suddenly stopped along the 1,120m course, leaving them hanging upside down.

Two carriages, each full with 32 passengers, came to a sudden halt at around 4.45pm on Tuesday after a safety sensor was activated.

One carriage stopped about 20m to 30m above the ground on its upward track while the other stopped just before reaching the terminal of the Jurassic Park-inspired Flying Dinosaur ride, reported Japanese media.

No injures were reported among the riders who were safely evacuated. The last person was stranded for two hours, according to Kyodo news agency.

A spokesman for the Osaka theme park said the suspension of the roller coaster was the result of the operator's priority on safety.

The park operator has apologised for the incident and said a defective part that controls the motor has been replaced, reported broadcaster NHK.

It resumed the ride on Tuesday night after a test run. Many park-goers were undeterred by the incident and queued up to take the ride as soon as operations resumed shortly after 7pm on Tuesday.

Horrible moment: Over 60 riders trapped 100 feet in the air for two hours after a roller coaster breaks down at the Universal Studios #Japan in Osaka on Tuesday pic.twitter.com/gNR3tPEJX1 — CGTN (@CGTNOfficial) May 2, 2018

But some visitors were apparently horrified by the incident.

A 42-year-old mother of three from the city of Hiroshima told Kyodo: "It's scary to think (what would have happened) if we had been on board. I don't want to ride it anymore."

A 24-year-old woman from the city of Kumamoto, who rode on the roller coaster shortly before the incident, said: "It's already a terrifying ride, so I want them to operate it safely."

The theme park was crowded on Tuesday with visitors due to Japan's Golden Week holidays from late April to Sunday.

The same roller-coaster ride had run into similar trouble in August and September last year. The ride was launched in March 2016, with the highest point hitting 37m above the ground.