Two Dutch explorers studying melting Arctic sea ice have apparently drowned after falling through thin ice, police said Monday.

Marc Cornelissen and Philip de Roo were last seen on April 6 heading north on skis from Resolute -- Canada's northernmost outpost.

Their base camp received an automated distress call last week, and immediately sent an aircraft to pick them up.

But the plane was unable to land on the ice, which was deemed too thin to support its weight.

The researchers' equipment and a sled dog were spotted in the vicinity of the beacon, near a hole in the ice. But the two men were nowhere to be found.

"It is very likely that they drowned (after) falling through the ice," Royal Canadian Mounted Police Sergeant Yvonne Niego told AFP.

According to the Cold Facts organization's website, the scientists were on a two-month mission to gather data for climate research in an area where summer sea ice cover was expected to be most resilient to warming.

Last Tuesday, one of the scientists reported warmer than expected temperatures and thin ice ahead of them, about 200 kilometers (125 miles) north of Resolute. In a voice recording posted online Cornelissen said: "Today was a good day." But he added, it was "too warm," which had led him to ski part of the way in just his underwear and boots.