A rotating gondola attraction at an amusement park in Suita, Osaka Prefecture, came to a halt Saturday, trapping nine people for half an hour, park officials and firefighters said.

None of the nine appeared to be hurt in the 3:35 p.m. incident at Expoland, according to the firefighters who rescued them from the ride.

Called the G-Force, the ride features gondola cars that ascend as high as 14 meters from the ground and then rotate. It can hold 40 people.

According to police and rescue officials, the gondola stopped in a virtually horizontal position about 9.7 meters from the ground. The ride became operational again as the rescuers were working to help the trapped riders.

Police said they suspect the ride's safety mechanism kicked in because the nine people were positioned so that the gondola was out of balance.