Nearly 100 ships pass the Hormuz Strait - who is getting through?

Just under 100 ships have passed through the Strait of Hormuz since the start of March, according to data analysed by BBC Verify, despite periodic attacks on shipping in the area by Iranian forces.

While some energy and everyday goods are still moving through one of the world's busiest shipping lanes, daily traffic is down about 95% since the Iran war began on 28 February.

Before the war, about 138 ships passed through the strait each day according to the Joint Maritime Information Centre, carrying one fifth of the global oil supply.

The data provided by shipping analysts Kpler shows 99 vessels passing the narrow strait so far this month, an average of just 5-6 vessels a day.

BBC Verify looks at the ships making the journey and the risks they are taking.

Our analysis indicates that about a third of these recent crossings were made by ships with connections to Iran.

These include 14 vessels sailing under Iran's flag and others under sanctions due to suspected links to Tehran's oil trade.

Nine other ships were owned by companies with addresses linked to China, while six listed India as their destination.

The analysis also reveals that several non-Iran linked ships have docked at the country's ports, including vessels owned by Greek companies.

Some ships successfully crossing the strait appear to be taking a longer route than usual.

Tracking data for a Pakistan-flagged oil tanker suggests it sailed close to the Iranian coast on its passage through the strait on 15 March, rather than the more widely used route through the middle.

Bradley Martin, senior researcher at the US defence think tank RAND Corporation, told us the ship was likely "responding to some set of directions from Iran".

He says its path could indicate the presence of mines, or an effort by Iranian officials to make the ship easier to identify.

By forcing vessels to reroute, ships are entering Iran's territorial waters and Tehran's maritime rules, says Michelle Wiese Bockmann from Windward Maritime Analytics.

"My takeaway is that Iran is closing and controlling the strait by the fear of attack and also the fear of mining.

"That's why everyone is having to go around and hug its territorial coastline instead of going through that international navigation channel," she told BBC Verify.

Michael Connell from the US-based Center for Naval Analyses agrees that ships are taking a different route.

"They probably have some agreement in place with Iranian authorities that if they stick to a defined lane they're safe."

Since the conflict began we have verified 20 commercial vessels attacked off the Iranian coast, not all of them in the direct vicinity of the Hormuz Strait.

On 11 March, the Thai-flagged bulk carrier Mayuree Naree was struck by two projectiles while attempting to pass through.

Three of the 23 crew members remain missing, believed to have been trapped in the engine room when the ship was hit.

The ship's owners told BBC Verify the surviving crew were "traumatised at sea when they were hit by two explosions".

Two other vessels - the Greek-owned Star Gwyneth and US-owned MT Safesea Vishnu - were also attacked the same day.

"Commercial shipping lanes cannot become battle zones," MT Safesea Vishnu's owner told BBC Verify.

One person died in the attack while the ship was anchored off Iraq. All 28 crew members were forced to jump into the water to escape the burning ship, Mr S V Anchan said.

"These men and women are not soldiers… they are professionals who keep global trade moving."

The mix of threats - drones, missiles, fast attack boats and potentially mines - presents a serious challenge, says Arun Dawson from the King's College Freeman Air and Space Institute.

"A traditional minesweeper which is conducting slow, painstaking work is going to find it tricky to hunt for mines and deactivate them if they are also under air and surface attack," he said.

Iran can also use geography of the strait to its advantage. Not only is the strait narrow and shallow, the coastline is also mountainous. This allows Iran to launch elevated attacks, which ships have less time to react to.

In an attempt to evade detection, many ships appear to be deliberately switching off their tracking system - known as AIS (Automatic Identification System).

"The vast majority of these [ships] have been crossing with their eyes off," says Dimitris Ampatzidis from Kpler.

By turning off their trackers as they enter the Gulf of Oman, boats are disappearing from maps and then reappearing hours or days later in a different location.

Although this helps ships conceal their position, it also presents challenges for firms like Kpler who are tracking movements in the strait.

"Everything has been validated by our analysts through manual verification… and by using satellite imagery as well," Ampatzidis told BBC Verify.

Additional reporting by Daniele Palumbo and Joshua Cheetham