A helicopter belonging to Pawan Hans Limited crashed in Bombay High on Wednesday night, said reports.
The Indian Navy has launched a full scale search and rescue operation (SAR) as two pilots who were on board are missing.
Two minor war vessels of the Indian Navy are looking for survivors. Destroyer INS Mumbai has also been dispatched to the area.
The tragedy occurred while the chopper was reportedly carrying out a night-landing practice on an oil rig.