An aquatic creature believed to be a pilot whale swims slowly with its dorsal fin jutting out of the water in a port in Kita-Kyushu on June 13. (Jun Kaneko)

KITA-KYUSHU--A large marine mammal that is believed to be a whale was spotted swimming in a port here with its head and dorsal fin jutting out of the water, drawing crowds of spectators.

The aquatic creature was seen by a fisherman in a port in Kokura-Kita Ward on the morning of June 12. It is thought to have strayed into the fishery port.

The mammal is about 4 meters long and from the shape of its head or dorsal fin is believed to be a short-finned pilot whale, according to Kaikyokan, an aquarium in Shimonoseki, Yamaguchi Prefecture, which is located next to Kita-Kyushu.

“(These kind of whales) are very powerful and are dangerous," an official of the aquarium warned. "So, please stay away from it.”