Aerial footage of the stranded creatures
Fishermen in the Philippines have rescued about 200 dolphins which became stranded in shallow waters near Manila.
Three of the dolphins were found dead and it was feared more would die unless they could be guided to deeper water.
They have been identified as melon-headed whales, which despite the name are a type of dolphin that travels in large pods of several hundred.
Beached dolphins are not uncommon in the Philippine archipelago but rarely occur in such large numbers.
Residents saw the huge pod of dolphins near the towns of Pilar and Abucay on the Bataan peninsula west of Manila.
The townspeople waded into the waters clapping and splashing to frighten the dolphins away, while the fishermen used their boats to guide the mammals out to deeper waters.
"This is an unusual phenomenon," Bureau of Fisheries and Aquatic Resources director Malcolm Sarmiento told local radio, adding there were more than 200 of the stranded mammals.
He said they could be reacting to a "heat wave or disturbance at sea" such as a possible major underwater earthquake.
"If their eardrums are damaged they become disorientated and they float up to the surface," he said.
Two of the three dead dolphins were reported to have damaged eardrums.
Dolphin beachings, in smaller numbers, are common in the Philippines, but it is rare for melon-headed whales to venture so close to shore as they prefer the deep waters of the open ocean.