A merchant ship issued a distress call after being struck in the Red Sea off Yemen, a security firm said on Wednesday, in what appeared to be the latest attack by Iran-backed Huthi rebels.

The ship was hit about 68 nautical miles southwest of the rebel-held port city of Hodeida, maritime security firm Ambrey said.

The company "assessed the vessel aligned with the Huthi target profile at the time of the incident", it said in a statement, without giving further details.

The Huthis, who are at war with a Saudi-led coalition after ousting the government from the capital Sanaa in 2014, have launched scores of drone and missile attacks on shipping in the Red Sea and Gulf of Aden since November.

They say they are harassing the vital trade route as an act of solidarity with Palestinians during the Israel-Hamas war in the Gaza Strip.