Russian naval assets are reportedly assisting a tanker seeking to avoid US detention off the coast of Venezuela.

Russia has sent a submarine and other naval assets to escort the Russian-flagged VLCC Marinera out of Venezuelan waters, where US forces are seeking to detain it, CBS News reported on Tuesday, citing comments from US officials.

The US has been pursuing the tanker since last month, and may attempt to sink it, according to the report. The US Justice Department has obtained a seizure warrant based on the ship’s prior involvement in the Iranian oil trade.

The tanker is reported not to be carrying a cargo at present.