Mataram, West Nusa Tenggara. Indonesian authorities are investigating a mysterious object resembling a torpedo that was found floating near the popular tourist island of Gili Trawangan, officials said on Wednesday.

The object was discovered on Monday morning by a fisherman, identified as 28-year-old Arianto, about 10 miles offshore. Alarmed by the find, he reported it to local police, prompting authorities to secure the site.

“It was found by a fisherman who immediately contacted local officers due to safety concerns,” said Colonel Aseptri Prabowo, commander of the Mataram Naval Base.

Within two hours, the object was transported to shore and cordoned off before being moved to the naval base in Mataram for further examination. Officials said the object was intact when recovered.

While its identity has not yet been confirmed, the navy has classified it as an “unidentified object,” although its shape bears a strong resemblance to a torpedo.

Initial measurements indicate the object is approximately 3.7 meters long and 65 centimeters in diameter.

“We handled the object with extreme caution from the moment it was discovered to ensure its condition remains unchanged,” Aseptri said.

A preliminary assessment by the police bomb disposal unit confirmed that the object does not contain explosives or radioactive materials.

However, its origin, function, and possible ownership remain unclear. Authorities have yet to determine whether it is a military device, an underwater survey instrument, or part of another system that drifted into Indonesian waters.

“There is writing on the object, but we cannot yet confirm whether it indicates a specific country of origin. This will be analyzed by experts,” Aseptri said.

No cameras or external electronic components were visible, though the object has not been dismantled pending further technical examination by the Navy’s headquarters in Jakarta.

According to Aseptri, the discovery marks the fifth such incident in Indonesia since 2017. It remains unclear whether the object poses any threat to national security.

“The assessment of whether it is dangerous will be determined by technical experts at headquarters. We are awaiting further results,” he said.

Following the discovery, the navy has increased patrols in the waters of West Nusa Tenggara. Coastal communities have been urged to remain calm and report any suspicious objects.

“We urge the public not to speculate. If you encounter unusual objects along the coast, report them immediately to authorities,” Aseptri said.

The object bears the marking “CSIC,” leading some media outlets to speculate it may be linked to China Shipbuilding Industry Corporation, a major manufacturer of naval vessels and underwater systems, though officials have not confirmed this.