China said it was seeking details of 25 of its nationals who were among the 61 crew members of two supertankers seized by Indonesia on suspicion of illegally transferring oil.
On the other hand Indonesia said it had seized the vessels after they were detected making the transfer from Iranian-flagged MT Horse to Panamanian-flagged MT Freya, which led to an oil spill.
Indonesian authorities said the seizure was not related to U.S. sanctions, which Washington imposed in an attempt to shut down Iran’s oil exports in a dispute over Tehran’s nuclear program.
The MT Horse, owned by National Iranian Tanker Company, and MT Freya, managed by Shanghai Future Ship Management Co, were detected off the island of Kalimantan in Indonesia.
Chinese Foreign Ministry spokesman Zhao Lijian said 25 of the crew members were Chinese, without distinguishing whether the crew was on one ship or split between the two.
“Our embassy has expressed its concern to Indonesia,” Zhao said. “We urge them to verify the situation of the Chinese sailors as soon as possible and inform us formally.”
He said China called on Indonesia to conduct an investigation “fairly and in accordance with the law.”
Indonesian Foreign Ministry spokesman Teuku Faizasyah told Reuters there had been “initial communication” with China and Iran, and said further discussion would depend on the results of the investigation.
Iran’s Foreign Ministry said on Monday that the seizure of its tanker was due to a technical problem and that it had asked Indonesia to provide more details.
Iran has been accused of trying to conceal the destination of its oil sales by disabling tracking systems on its tankers.
Indonesian authorities said the ships concealed their identity by not displaying national flags, turning off automatic identification systems and failing to respond to a radio call.
The International Maritime Organization (IMO) requires ships to use transponders for safety and transparency reasons. Crews can turn off the devices only if there is a danger of piracy or similar hazards.
“We welcome the Indonesian Coast Guard’s efforts to counter illicit maritime activity,” a spokesman for the U.S. embassy in Jakarta told Reuters, saying Washington supported efforts to ensure IMO standards for safety and environmental compliance are maintained.