About 150 dolphins have beached themselves on Japan's northeastern coast, and efforts are underway to help them.

Officials said the dolphins were stranded on the beach in Hokota, a coastal city northeast of Tokyo, over a stretch of about 6 miles.

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

Television footages 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, measuring between 2 to 3 yards long.

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