Two Czech tourists jumped into an icy river in an attempt to escape with fossils from B.C.'s Burgess Shale Formation last week.

Omar McDadi, a communications officer with Parks Canada, said the incident was bizarre only because of how far the pair went in an attempt to get away.

"We've had thefts from the Burgess Shale before, but never dramatic escape attempt like this," McDadi said.

The Burgess Shale in Yoho National Park is the home of fossils that date back more than 500 million years.

It was designated a UNESCO World Heritage Site in 1981, and is legally accessible only by guided tours. Taking anything from the park is strictly prohibited.

Pair caught, fined

The Czech tourists were first stopped by a Parks Canada warden in the afternoon on July 30 after a guide began to suspect the pair had taken something from the protected site.

McDadi said the pair slipped away from the warden who confronted them, but were later spotted in the nearby hamlet of Field, B.C. That's when the situation escalated.

"They fled and ran into the Kicking Horse River, which is a really dangerous thing to do," McDadi said.

"It's a very fast moving river with high water levels this time of year."

Both men were rescued and there were no injuries. They are expected to return to the Czech Republic shortly.

Parks Canada issued fines of $115 each to the accused thieves and returned the six shale pieces to the park.

With files from the CBC's Geoff Ellwand and Sonya Denton