A month after a stray orca died in the Seine River in France, another large whale has been sighted in the river's estuary near Le Havre.
The ten-meter-long animal, which was seen by several ship crews on Thursday, could be a fin whale, the prefecture in Rouen said.
The appearance of some of these whales on the coast is not unusual, the animals are also able to feed themselves there, it said.
The sighted whale makes a healthy impression.
The prefecture convened a team of experts to keep an eye on the situation.
Ships were instructed to keep a distance of 100 meters from the marine mammals if possible.
The orca that died in the same area of the Seine at the end of May had been suffering from an illness.
Unlike the fin whale, it was also in unusual waters for it.
Attempts to guide the orca towards the sea using whale sounds had previously failed.