8 dolphins dead after washing ashore in New Jersey

Rescuers poured sea water to try and revive the dolphins

A coastal mystery continues along the eastern US, as eight dolphins were found washed ashore in New Jersey on Tuesday.

They landed about 20 miles south of Atlantic City where relief teams spent hours working to revive the animals.

Two of the dolphins died before workers arrived. The other six were euthanised to "prevent further suffering".

Over a dozen dead whales have been found along the US East Coast since December.

The dolphins arrival to Sea Isle City adds to the mystery of recent marine deaths along the eastern US.

Video coverage from BBC's US media partner CBS shows officials from the Marine Mammal Stranding Center as they poured seawater over the dolphins, struggling to keep them alive.

"The decision was made to humanely euthanise the dolphins to prevent further suffering, as returning them to the ocean would have only prolonged their inevitable death," the Marine Mammal Stranding Center posted on Facebook.

All eight dolphins were brought to a lab for post-mortem examinations to be performed.

The deaths come after two other dolphins died recently on a different beach in New Jersey last week. One of the dolphins there was found dead and the other - a calf - was euthanised due to its unlikeliness to survive.

"We share in the public's sorrow for these beautiful animals, and hope that the necropsies will help us understand the reason for their stranding," said the Marine Mammal Stranding Center in a statement.

Unusual marine activity along the US East Coast has risen the last few months.

A recent uptick in whale strandings along the mid-Atlantic coast has also been noted by officials from the National Oceanographic and Atmospheric Administration (NOAA).

They have been tracking the "unusual mortality" of humpback whales along the eastern shores since 2016. However, the discovery of over a dozen dead whales since December has raised the alarm.