Google on Saturday deleted from its maps service dozens of images of Austrian landmarks that were altered by environmental activists to highlight the potential impact of climate change.

The images, changed using artificial intelligence, showed the river Danube and Austrian lakes dried up and snowless Alpine peaks as though the pictures were taken in the year 2070.

They were put on Google Maps this week by the Letzte Generation (Last Generation) group.

"Our policies clearly prohibit content that is not based on real experience or does not accurately represent a location. We are removing the policy-violating photos in question," a Google spokesperson told AFP.

Letzte Generation said it was "not very surprised" by Google's action.

"They are ignoring the climate catastrophe, just like authorities and big companies in general," said group spokesperson Marina Hagen-Canaval.

The group said earlier that it had posted the pictures on Google Maps to alert tourists who use the service to prepare their holidays of the risks of rising temperatures caused by climate change.

Letzte Generation has staged other protest stunts including blocking highways and has vowed to take more action, including on the internet.