TOKYO — About 150 dolphins beached themselves and became stranded on Japan’s northeastern coast, and people were working Friday to save them.

The dolphins were lying on a stretch of about 6 miles of beach in Hokota, a coastal city northeast of Tokyo.

Some of the dolphins, mostly melon-headed whales or blackfish, were found alive but were extremely weak and later died.

Television footage showed dozens of people carrying buckets and pouring sea water over the dolphins, or even covering them with bath towels, to keep them from drying up.

City authorities, the coast guard and an aquarium were working to rescue the dolphins, which are between 2 to 3 yards long.

Public television NHK reported that the coast guard transported three in good health off shore and released them.

Smaller beachings have occurred over the last 15 years, including some 50 dolphins on a nearby coast in 2011.