Attacks on tankers in and around the Strait of Hormuz continue to highlight risks facing energy shipping, while Baltic Exchange data shows that earnings for vessels transporting crude from the Gulf to China remain elevated.

The UK Maritime Trade Operations (UKMTO) issued alerts documenting at least eight attacks in and around the waterway between Oct. 1 and 5, involving vessels struck by unidentified projectiles, The Caspian Post reports, citing Anadolu Agency.

In an incident on Monday, a tanker’s master reported that the vessel was hit by a projectile, triggering a fire in the engine room. No casualties or environmental impact had been reported when the alert was issued.

Other reports detailed attacks over the weekend involving crude oil tankers and a liquefied petroleum gas carrier.

UKMTO also said a tanker entering the strait on Monday was contacted by Iran’s Islamic Revolutionary Guard Corps 11 nautical miles north of Khasab, Oman.

The vessel was told to turn back or risk being targeted, and its master confirmed that the instruction had been followed, according to the agency.

UKMTO did not attribute the projectile attacks to any specific party in the alerts reviewed. It said investigations were underway and advised vessels to exercise caution while transiting the area and report any suspicious activity.

According to the Baltic Exchange’s Oct. 2 tanker report, daily round-trip time-charter-equivalent earnings on the Middle East Gulf-China route stood at $1,221,893 for a standard very large crude carrier.

The benchmark is based on shipments of 270,000 metric tons of crude and represents estimated daily vessel earnings after voyage-related expenses.

The exchange said the market had strengthened again after weakening earlier in the week, although freight rates on the route remained slightly below the previous week’s level.