Ships have largely been avoiding the Strait of Hormuz after an escalation in which Iran fired what appeared to be warning shots at vessels and the US military seized an Iranian cargo ship, Reuters reports.

Just one ship exited the Gulf through the strait while two entered in the space of 12 hours, ship-tracking data showed, a fraction of what is usually about 130 vessels per day.

The oil products tanker Nero, which is under British sanctions for Russia-related activities, was sailing through the strait, satellite analysis from SynMax and tracking data from the Kpler platform showed.

Two other ships — the chemical tanker Starway and Axon I, a liquefied petroleum gas tanker under US sanctions for past trading with Iran — were sailing into the Gulf.