Story highlights

NEW: All 13 people on board are believed to be dead

Helicopter carried 2 pilots, 11 passengers; it was flying from an oil platform in the North Sea

CNN  — 

A helicopter carrying workers from an oil platform to the mainland crashed off the coast of Hordaland, Norway, on Friday, most likely killing 13 people, according to police.

Two people were still missing when rescue operations stopped Friday afternoon.

It’s not clear whether anyone survived the crash, but the rescue and recovery effort was halted at 5 p.m., officials said.

“The searches have concluded. We are no longer searching for the last two passengers,” said Eorte Galti, with the Joint Rescue Coordination Centre Southern Norway.

“Witnesses have said the rotor of the helicopter was seen flying away from helicopter before it crashed, but I cannot confirm,” Galti said.

The helicopter carried two pilots and 11 passengers and was flying from an oil platform in the North Sea to the city of Bergen. The victims were employed by different companies, but were all working for Norway-based energy company Statoil, according to a statement on the company website.

This was “one of the most severe helicopter accidents in the history of the Norwegian oil industry,” said Statoil’s Arne Sigve Nylund, executive vice president development and production Norway.

“It is with great sorrow we have received the message that 13 people have been involved in this accident,” he said.

The crash happened 50 minutes into the flight with 10 minutes remaining to landing in Bergen on the mainland, the company said.

Statoil has temporarily grounded all traffic helicopters to its platforms.

Hordaland is about 250 miles west of Oslo, the Norwegian capital.