The latest advisory from the UK Maritime Trade Operations Centre has maintained the threat level in the Strait of Hormuz as “moderate” — down from the “substantial” threat it warned of two days ago, Al Jazeera reports.

The advisory said the southern route through the key Gulf waterway, which runs close to Oman, is open “day or night”.

“However, mariners should be advised of the existence of mines and expect naval presence as clearance operations continue,” it added.

The advisory also “strongly” advised ships to use the Naval Cooperation and Guidance for Shipping, a system developed by Nato that the alliance describes as an “interface between military operations and merchant shipping”.