A Singapore-registered container ship has sunk after being struck by an unknown projectile in the Strait of Hormuz, the Maritime and Port Authority of Singapore said Wednesday. CNA and the BBC also reported the sinking.

The ship, GFS Pride, was hit on Oct. 13, Singapore time, the authority said. It suffered damage and a fire on board and later sank. All 21 crew members were safely evacuated, and no injuries were reported, the MPA said.

A second Singapore-registered container ship, GFS Giselle, was struck on Oct. 14, the authority said. It suffered hull damage but reached a safe anchorage under its own power. All 22 crew members are safe, the MPA said. No Singaporeans were on board either ship.

The MPA said it is "deeply concerned about the continued attacks on commercial shipping in the Strait of Hormuz." It called the attacks "unprovoked, unjustifiable, and a breach of international law."

Iran's Revolutionary Guards said a ship hit naval mines and sank while passing through what they called an "unauthorised" route in the strait, the BBC reported. The Guards released photos that appeared to show black smoke rising from a container ship, the BBC said.

The Hydrographer of Pakistan warned sailors that GFS Pride had sunk about 4 nautical miles northwest of Ras al-Sheikh Masud in Oman's Musandam Peninsula, the BBC reported.

At least 24 seafarers have been killed in 106 confirmed incidents since the war with Iran began in February, according to the UN's International Maritime Organization, the BBC said. Only one other ship, the Malta-flagged Safeen Prestige, was reported to have sunk in that time, the BBC said. CNA also reported that GFS Pride is the second ship to sink since the war began, citing IMO data.

What we know: GFS Pride sank and GFS Giselle was damaged, with all crew safe.
What we don't: What struck the ships, and whether the Guards' mine claim refers to GFS Pride.