Atleast four persons were killed after an Oil and Natural Gas Corporation Limited (ONGC) Pawan Hans chopper made an emergency landing in the Ariabian Sea on Tuesday morning.
There were seven passengers and two pilots on board the chopper.
The accident happened 175 kilometers off the Mumbai coast near ONGC's Sagar Kiran oil rig.
In a joint opration of ONGC, the Indian Navy and the Coast Guard, all the nine on board the chopper were rescued by late Tuesday afternoon. However, four of the rescued who were brought out in an unconscious state later died in hospital.
The exact reason why the chopper had to be ditched into the sea is not known yet.