More than 200 dolphins beached in Manila Bay

Residents try to drive away melon-headed whales in shallow waters off Manila Bay in Bataan province about 60 miles west of Manila. The unusual convergence of about 200-300 melon-headed whales prompted a massive rescue attempt by hundreds of volunteers and fishermen who drove them back to deeper seas Photograph: HO/AP

More than 100 dolphins were beached in Pilar town in Bataan province – at least three of them were already dead, a local official said Photograph: Philippine Coast Guard/EPA

Filipino villagers swim with stranded dolphins off Orion town. Marine experts were summoned to the area to help Photograph: Dennis M. Sabangan/EPA

The unusual convergence of about 200-300 melon-headed whales prompted a massive rescue attempt by hundreds of volunteers and fishermen who drove them back to deeper seas Photograph: Dennis M. Sabangan/EPA

Volunteers rescue a young dolphin. Dolphins with injured eardrums become disoriented, cannot dive for food and are too weak to swim Photograph: Bullit Marquez/AP

Veterinarians and harbour police come to the aid of a weak melon-headed whale along the coast of Balanga in Bataan province, north of Manila Photograph: Romeo Gacad/AFP/Getty Images

Veterinarian Riza Salinas injects antibiotics into a weak dolphin. If the leader of the pod is sick, the animal needs to be identified and taken out of sight of the rest of the pod so the healthy dolphins can be taken back to the deep sea Photograph: Romeo Gacad/AFP/Getty Images

Filipino fishermen swim with the stranded dolphins. Fisheries officials coordinated with private groups and fishermen to stop the dolphins from being beached and prevent more deaths. Wardens were positioned around the area and fishermen warned not to harm them Photograph: Dennis M. Sabangan/EPA

Beached dolphins are common in the Philippine archipelago of more than 7,000 islands, but very rarely occur in such huge numbers Photograph: Bullit Marquez/AP

Melon-headed whales are considered threatened species meaning they are likely to become endangered in the future. They are related to the pygmy killer whale and pilot whale Photograph: Dennis M. Sabangan/EPA