Oslo - A combination of strong winds, high waves and icy waters contributed to the deaths Wednesday of four German tourists whose rented fishing boat overturned off the Norwegian west coast, north of Trondheim, police said Thursday.

"Our probe has suggested that the boat and equipment were in order," local police chief Tor Flasnes told Deutsche Presse-Agentur dpa.

The police probe suggested that the rented boat was likely caught by a wind gust at the top of a wave and overturned as the men were heading back to land, Flasnes said.

There was also a noticeable headwind.

The four men - aged 51, 52, 69 and 70 - fell into the cold sea, he said.

"The water was only 7 degrees Centigrade and the men were believed to have suffered from hypothermia before they subsequently drowned," Flasnes said.

A rescue helicopter and other boats were quickly at the scene but the men were dead when salvaged from the icy waters.

Flasnes said the deceased where from Zeitz in the eastern state of Saxony-Anhalt.

Local Norwegian media said they belonged to the same fishing club.

The rented boat was a 17-foot aluminium boat with an outboard engine.

The bodies were Wednesday transported to the University Hospital in Trondheim for formal identification, and Flasnes said the process to send the bodies back to Germany was underway. (dpa)