Almost 150 dolphins have washed up on a beach in Japan sparking a frantic rescue effort by locals and coastguards. A number of the melon-headed whales – a member of the dolphin family – have already died and are to be buried, AFP reports.

Teams are working to try to stop the skin of the dolphins from drying out, while others were carried in slings back into the ocean.

Melon-headed dolphins are normally found in the deep ocean and are fairly common in Japanese waters. Normally one or two are beached a year. In 2011, 50 melon-headed whales were beached in a similar area but the numbers seen in Hokota, Ibaraki, is unprecedented said a coastguard.

The reason for the beaching is unknown. Tadasu Yamada, a researcher with the National Museum of Nature and Science said they could have got lost.

"Sonar waves the dolphins emit might have been absorbed in the shoals, which could cause them to lose their sense of direction," he told the Yomiuri Shimbun.

The creatures were found strewn along a 10km-long stretch of beach. Many of them had suffered injuries with video footage showing them with deep cuts to their skin. "They are alive. I feel sorry for them," one local told public broadcaster NHK.

beached dolphins
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beached dolphins
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beached dolphins
Beached dolphins in JapanAFP/Getty Images
beached dolphins
AFP/Getty Images
beached dolphins
AFP/Getty Images
beached dolphins
AFP/Getty Images
beached dolphins
AFP/Getty Images