A merchant vessel was "taking on water" off the Yemeni port of Hodeida on Tuesday after it was damaged in a missile attack, maritime security firm Ambrey said.
The ship was "targeted with three missiles," Ambrey said, adding that a distress call said it "had sustained damage to the cargo hold and was taking on water".
The distress call also reported that "the vessel was listing", Ambrey added.
The firm did not identify the ship or say how many crew members were on board.
The United Kingdom Maritime Trade Operations, which is run by Britain's Royal Navy, said it "has received a report of an incident" southwest of Hodeida, without elaborating on the nature of the attack.
"Authorities are investigating," it said, advising ships to exercise caution.
There was no immediate claim of responsibility for the attack, which came amid a campaign of drone and missile strikes against Israeli-linked shipping by Yemen's Iran-backed Huthi rebels.
The rebels' attacks, which they say are in support of the Palestinians, have prompted some shipping companies to detour around southern Africa to avoid the Red Sea, a vital route that normally carries about 12 percent of global trade.
Since January, the United States and Britain have launched retaliatory strikes on Huthi targets in Yemen in response to the attacks on shipping.
The strikes have done little to deter the Huthis, who have vowed to target US and British vessels as well as all ships heading to Israeli ports.
On Monday, US military forces destroyed a drone over the Red Sea launched from a Huthi-controlled area of Yemen, US Central Command (CENTCOM) said in a statement.
In March, a ship loaded with fertiliser sank in the Gulf of Aden after it was damaged by missiles launched by the Huthi rebels.
In November, the Huthis seized the vehicle-transporter Galaxy Leader and its crew.
Speaking from the United Arab Emirates on Tuesday, the prime minister of Yemen's internationally recognised government criticised the Huthi attacks on Red Sea shipping.
"The Huthis are exploiting" the Palestinian cause to launch strikes, Ahmed Awad bin Mubarak said, charging that Huthi threats to Red Sea shipping predate the Gaza war.
ho/kir