Authorities found more dolphins washed ashore in Japan on Tuesday, several of them dead.
At least eight more dolphins were found Tuesday along the shores of Isumi and Ichinomiya in Chiba province on the Pacific coast of Japan.
Local authorities said 33 dolphins were stranded on the shores on Monday.
A total of seven are likely dead, Tokyo-based Kyodo News reported.
Authorities and surfers helped the surviving animals return to the ocean.
Dolphins are each around two meters (6.6 feet) long.
"They may have weakened from swimming too close to the coast where the water is cold," Yukio Miyauchi, head of the Choshi Ocean Institute in Chiba province, said Monday.
Researchers from Japan's National Museum of Nature and Science will be analyzing the dead dolphins.
