London (AFP) - Here are the latest key facts about security alerts and trade impacts from the blockage of the Strait of Hormuz, a crucial shipping route virtually paralysed by the Middle East war.

Around a fifth of global crude oil and liquefied natural gas (LNG) passes through the waterway in peacetime.

The war erupted on February 28 when the United States and Israel began bombing Iran, prompting Tehran to retaliate with strikes across the region and restrict access to the strait.

- Tanker hit in Qatar waters -

In total 27 commercial ships, including 13 tankers, have been attacked or reported incidents since March 1 in the Gulf, the Strait of Hormuz, or the Gulf of Oman, according to British marine security agency UK Maritime Trade Operations (UKMTO).

In the latest incident, a tanker leased to Qatar’s state-owned energy company was struck by an Iranian missile in the Gulf country’s territorial waters, officials there said Wednesday.

They said 21 crew members were evacuated without any casualties.

UKMTO said the vessel had been struck by “two projectiles” north of Ras Laffan, the world’s largest LNG hub.

It noted “one projectile caused a fire, which was extinguished, and another “remains unexploded within the vessel’s engine room”.

- 11 sea workers killed -

Since the conflict began, at least 11 seafarers or dock workers have died in incidents in the region, according to the International Maritime Organization (IMO).

The UN agency updated that tally Tuesday, after formally confirming the deaths of three seafarers aboard the Thai bulk carrier the Mayuree Naree, which was attacked while transiting the strait on March 11.

- Handful of crossings -

Just seven vessels crossed the strait on Tuesday and to 1500 GMT Wednesday, according to maritime intelligence firm Kpler.

Since March 1, commodities carriers made 218 crossings, according to Kpler data, a 94 percent decrease on peacetime.

Of these, 135 were by oil tankers and gas carriers and most were travelling east out of the strait.

Six out of 10 crossings involved ships coming from or heading to Iran. The United Arab Emirates accounted for 22 percent, India 15 percent, China 14 percent and Saudi Arabia nine percent.

The channel in peacetime sees around 120 daily transits, according to shipping industry intelligence site Lloyd’s List.

- 2,000 ships in Gulf -

Bloomberg data showed Wednesday that 2,190 vessels sent transponder signals in the Gulf west of the Strait of Hormuz over the past day.

Of those, 327 were oil and gas vessels, including 12 very large gas carriers and 50 very large crude carriers.

- Iran-approved route -

Recent crossings appeared to have mainly used a route apparently approved by Iran around Larak Island just off the country’s coast.

Leading shipping journal Lloyd’s List on Tuesday estimated at least 48 ships had used it since last week, the majority with links to Iran.

The Revolutionary Guards said the route was closed to vessels travelling to and from ports linked to Iran’s “enemies”.

- 46% sanctioned ships -

Since the war started, 46 percent of the crossings have been by ships under US, EU or UK sanctions, according to an AFP analysis of passage data.

Of the crossings by oil and gas tankers, 63 percent were by vessels under sanctions.