Jakarta, June 11 -- Indonesia's Navy has foiled an attempt to smuggle strategic raw minerals through waters off Batam in the Riau Islands Province after inspecting vessels suspected of carrying prohibited export cargo, the Navy said on Thursday.

According to a Navy statement received in Jakarta, the case began when warship KRI Kujang-642-operating under Fleet Command I of the Maritime Security Task Force-detected suspicious movements by tugboat Capricorn 106 and barge Capricorn 92.210 on May 16.

The Navy subsequently boarded and inspected both vessels through elements of the Indonesian Fleet Command. The inspection found cargo containing rare earth elements and other hazardous radioactive materials, the statement said.

The boarding was...