At least two people have died and 25 are still missing after an Indian oil industry helicopter crashed into the sea off the country's west coast near Bombay (Mumbai).
Rescuers have so far found only two survivors, and rough seas are hampering the search.
The helicopter went down shortly after taking off from an oil rig carrying 29 employees of India's giant Oil and Natural Gas Corporation (ONGC).
The cause of the crash is unclear.
ONGC spokeswoman Narayani Mahal said three people were immediately rescued, but one died later in hospital.
The body of the pilot was also recovered.
However, she added: We are hopeful of finding more survivors since they were all wearing life jackets".
Two ONGC helicopters, divers and support vessels are helping the coast guard and navy with the rescue.
The helicopter crashed three minutes after taking off at 1215 local time (0645 GMT) from the Sagar Kiran rig in the Neelam oil field, about 100 kilometres from the Bombay coast.
"It was a very short flight of about 35 km from the oil rig to the helicopter base on shore for a crew change," said Ms Mahal.
The aircraft, an Mi-172 Russian helicopter, had been chartered by ONGC, the company said.
The accident took place in Bombay High, India's largest oil field, which produces about half of the country's crude output.