At least four people dead and 12 critically injured in US tour bus crash

At least four people are dead and 12 are critically injured after a tour bus carrying tourists crashed near a national park in the US state of Utah.

A bus carrying Chinese-speaking tourists careened off a road and crashed near Bryce Canyon National Park on Friday, killing at least four people and critically injuring at least another 12, authorities reported.

The cause of the crash, which occurred late in the morning (local time) on State Route 12 just west of the park, was under investigation.

But weather did not appear to be a factor, State Highway Patrol and Garfield County Sheriff's Department officials said.

A total of 30 people, including the driver, were aboard the bus when it ran off the road, rolled into a guard rail and flipped onto its side, sheriff's spokeswoman Denise Dastrup said by telephone.

At least four people are dead and multiple others critically injured after a tour bus crash outside Bryce Canyon National Park in Utah. Source: AAP

All 26 people aboard who survived were injured and were taken to various hospitals with injuries ranging from minor to life-threatening, she said.

The Highway Patrol said 12 to 15 people on the bus were critically injured.

Ms Dastrup said seven victims were initially listed as critical and four of them were evacuated to hospitals by helicopter.

She said the passengers were all Mandarin-Chinese speakers and county officials put out a call for Mandarin speakers to go one of the local hospitals to assist in translation.

The victims' nationalities had not been immediately determined, officials said.

Highway Patrol spokesman Corporal Chris Bishop said the passengers were all believed to be from mainland China or Taiwan as opposed to being US residents.

"This is pretty overwhelming for a little county of 4900 people," Garfield County Commissioner Leland Pollock told local NBC affiliate KSL-TV.

"This is just horrible for us, and we feel terrible for those who are injured and their families."

Emergency medical services personnel assist victims of a bus crash near Bryce Canyon National Park. Source: AAP

Comm Bishop said based on the number of critically-injured victims, it was possible the death toll would rise.

A 23-kilometre stretch of highway around the crash site was shut in both directions as authorities began investigating the cause of the accident, and it likely will remain closed "for some time", Comm Bishop said.

Bryce Canyon National Park, best known for its spired, multi-hued rock formations called hoodoos, remained open to visitors, though traffic to the park was restricted.

While all inbound routes to Bryce Canyon from the north, south and west pass were blocked by the crash site on SR-12, alternate routes from the west were still open, park spokesman Peter Densmore said.

At the time of the crash, the bus was headed toward Bryce Canyon, located about 435 km south of Salt Lake City, and skies were clear, Ms Dastrup said.

The national park, occupying 14,245 hectares of southern Utah, attracts some two million visitors a year.

Do you have a story tip? Email: newsroomau@yahoonews.com.

You can also follow us on Facebook and Twitter, download the Yahoo News app from the App Store or Google Play and stay up to date with the latest news with Yahoo’s daily newsletter. Sign up here.