A double-decker tour bus crashed into a steep ravine in a scenic mountain area in southern Taiwan, killing 22 and seriously injuring two dozen others, officials said Monday.

The injured, including 16 children, were treated for broken bones and other injuries, said a spokesman of the Kaohsiung municipal government, where most of the bus passengers came from.

"As we understand, the injured were all in pretty serious conditions," Hau Chien-sheng said.

Taiwanese media quoted witnesses as saying most of the victims were thrown from the vehicle's broken windows as the bus tumbled down the ravine Sunday.

"Their bodies hit the boulders as they were tossed out and they died on the spot," the United Daily News quoted eyewitness Liu Chien-chen as saying.

Prosecutor Lin Chih-feng said the cause of the accident was being investigated.

The tour bus was 18 years old but had recently passed a safety inspection, Transport Minister Tsai Tuei said. Authorities will consider lawmakers' demands to restrict older buses from driving on mountainous roads, Tsai told lawmakers Monday.