The US Treasury Department sanctioned an oil tanker it says is involved in shipping Iranian commodities in support of Houthi rebels.

The Marshall Islands-flagged Lady Sofia is en route to China after receiving an unspecific cargo from another sanctioned vessel, Mehle. The so-called ship-to-ship transfer occurred on Jan. 31 near Singapore, with the Mehle disguising its true location through “spoofing,” according to a statement from the Treasury Department.

The US also sanctioned Vishnu Inc., which owns and operates the Lady Sofia.