An excursion plane carrying eight passengers from a Holland America Line cruise ship crashed on Thursday in southeast Alaska, the company said.

The crash occurred near Ella Lake, about 20 miles (30 km) northeast of the town of Ketchikan, the Seattle-based company said in a statement.

The small float plane was owned by Promech Air and carried eight passengers from the cruise ship Westerdam and a pilot, it said. The ship left Seattle on Saturday.

"The condition of those onboard the plane is not known at this time," the statement said. The excursion flight was sold through Holland America Line, a unit of Carnival Corp.

US Coast Guard and local search and rescue teams were on their way to the site of the accident, it said.

Anchorage, Alaska, CBS affiliate KTVA quoted a spokeswoman for the Alaska State Troopers as saying the plane was found on a rock face about 800 feet (240 metres) above Ella Lake.

Representatives from the Alaska State Troopers, Coast Guard and National Transportation Safety Board were not immediately available for comment.