Reuters reported that Iranian and Panamanian tankers were "seized by Indonesian authorities for suspected illegal oil transfers."
A spokesman for Indonesia's coast guard told the station that the vessels were caught transferring oil from one to the other, creating an oil spill during the operation.
Iran asked for an explanation on the incident citing "technical issues" as the real reason behind the move.
The report states that Iran has attempted to conceal the size and destination of its oil exports, skirting US sanctions.