The US Treasury Department has issued sanctions against four Iranian officials on the same day that Tehran’s navy seized a US-chartered tanker.

There is no clear link between the two incidents, as the department’s Office of Foreign Assets Control (Ofac) made no mention of the tanker seizure in the new sanctions.

But the incident adds to tit-for-tat blows between Washington and Tehran, with some seeing Iran’s seizure of the 159,000-dwt Advantage Sweet (built 2012) as a response to US crude seizures.