An elderly local resident found 80 kilograms (175 pounds) of the drug inside backpacks that were tied together and reported it to police, Jiji Press and other media said.
The bags were outfitted with a buoy and illuminated markers and authorities suspect that they were lost by seafaring traffickers, the reports said.
Police reportedly said the drugs had an estimated street value of USD 48 million. Local authorities declined to comment on the reports when contacted by AFP.
Mumbai Roundup: 9 incidents that took place this week
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