At least 4 dead, others critically hurt in Utah tour bus crash: Officials

At least four people are dead after a tour bus rolled over on a Utah road, ejecting some passengers, authorities said.

Thirty people, including the driver, were on board when the bus rolled over near Bryce Canyon National Park on SR-12, Garfield County Sheriff's Office spokeswoman Denise Dastrup said.

The Utah Highway Patrol released the names and ages of the deceased victims -- three women: Ling Geng, 68, Xiuyun Chen, 67, Zhang Caiyu, 62, and one man, ZhongLiang Qiu, 65. All are from Shanghai, China.

"Everyone on the bus sustained some sort of injury," Dastrup said.

The Intermountain Hospital Group said it had received 22 total patients at its facilities; 19 at Garfield Memorial, three at Sevier Valley and five have been transported for further care. Officials initially said three were in critical condition, 11 were in serious condition and three were in fair condition.

There appeared to be "no obvious explanation for the rollover," Garfield County Sheriff James Perkins told ABC News. He said the crash was on "part of the road that had a slight gradual turn," but "not much of a turn."

The Utah Highway Patrol said the bus was carrying Chinese speaking tourists into Bryce Canyon. Following the crash, the Chinese Embassy said it's monitoring the situation.

"We are saddened to hear about the accident in Utah involving a bus carrying Chinese tourists," the Embassy said in a statement. "The Embassy has initiated its emergency protocols, sent personnel to the area, and will assist the victims as needed."

SR-12, about 3.5 miles west of the park, is now closed in both directions. The national park remains open.

ABC News' Matthew Fuhrman contributed to this report.