ANCHORAGE — All those on board two small planes died in a midair collision Wednesday in western Alaska, state troopers said.

Troopers did not say how many people were in the two aircraft, but the Alaska National Guard said earlier that there were a total of five on board the planes.

Troopers said the crash occurred northwest of the village of Russian Mission, 375 miles west of Anchorage. Responders at the scene have confirmed there were no survivors on either of the planes, troopers said.

The crash scene covers a large area that is accessible only by helicopter, said Clint Johnson, the head of the National Transportation Safety Board’s Alaska division.

The collision occurred just before 11 a.m. Wednesday, Guard officials said.

Johnson said an initial report was about a possible plane crash involving a Piper PA-18 in the area of Russian Mission, followed shortly after that with another report of another, separate plane that was overdue. “And then subsequently, shortly after that, is when we started putting two and two together as far as a possible midair,” he said.

The planes involved in the crash are a Hageland Aviation Cessna 208 Caravan carrying three people and a Renfro’s Alaskan Adventures Piper PA-18 super cub with two people aboard, according to the Guard. A Guard helicopter with medics on board left Bethel around noon to head to the crash site.

Representatives of Hageland, which is operated by Ravn, Alaska, did not immediately respond with comment. A Renfro employee said the company was not immediately releasing information.

National Transportation Safety Board investigators were headed to the crash scene Wednesday afternoon, Johnson said.