Yemen's Iran-backed Houthis on Friday threatened to escalate attacks on Red Sea shipping after overnight strikes by the United States and Britain killed 16 people, according to rebel media.
The toll reported by the Houthis' Al-Masirah TV, which AFP could not independently verify, would constitute one of the deadliest strikes since the United States and Britain launched their campaign to counter disruption of the vital trade route in January.
The Houthis, who control much of Yemen, have launched scores of drone and missile attacks on vessels in the Red Sea and Gulf of Aden since November, citing solidarity with Palestinians in the Gaza Strip over the Israel-Hamas war.
The US Central Command, or CENTCOM, said 13 Houthi sites were targeted in a bid to degrade their ability to attack shipping.
"The American-British aggression will not prevent us from continuing our military operations," Houthi official Mohammed Al-Bukhaiti said on X, formerly Twitter, vowing to "meet escalation with escalation".
AFP journalists heard loud explosions in the capital Sanaa and the port city of Hodeida overnight from Thursday to Friday.
Strikes also targeted telecoms infrastructure in the town of Taez, Al-Masirah reported.
Citing health authorities, the TV station said 16 people were killed and more than 35 were wounded in Hodeida alone, without specifying if they were civilians or militants.
Al-Masirah also broadcast a video purporting to depict bloodied men wounded in a strike on a building housing a radio station in Hodeida.
The channel showed victims receiving treatment at a hospital, although AFP could not independently verify the authenticity of the images.
A hospital employee in Hodeida said "many" militants were among those killed and wounded in the attack, but was unable to give exact figures.
The British defence ministry confirmed its warplanes launched strikes in "a joint operation with US forces against Houthi military facilities".
The ministry said intelligence indicated two sites near Hodeida had been involved in the attacks on shipping, "with a number of buildings identified as housing drone ground control facilities and providing storage for very long-range drones, as well as surface to air weapons".
Another "command and control" site had been identified further south, it said in a statement.
British Prime Minister Rishi Sunak said "the strikes were taken in self-defence in the face of an ongoing threat", claiming the rebels have launched 197 attacks since November.
The overnight strikes were "necessary to protect our forces, ensure freedom of navigation, and make international waters safer and more secure", CENTCOM said in a statement.
Since January, the United States and Britain have launched strikes on Houthi targets in Yemen in response to the rebels' harassment of shipping.
In February, the Houthis held a mass funeral in Sanaa for 17 fighters they said were killed in US and British strikes.
The reprisal attacks have done little to deter the rebels, who have vowed to target US and British vessels as well as all ships heading to Israeli ports.
The rebels said Wednesday that they had attacked a Greek-owned bulk carrier and several other vessels in response to Israeli strikes on Rafah in the Gaza Strip.
The bulk carrier Laax, a Marshall Islands-flagged and Greek-operated vessel, reported being hit by three missiles, according to CENTCOM and maritime security firms, but was able to continue its voyage.
Also on Wednesday, the Houthis said they shot down a US MQ-9 Reaper drone with a surface-to-air missile, claiming it is the sixth such aircraft they have downed in recent months.
Among the biggest Houthi attacks, in March a ship loaded with fertiliser sank in the Gulf of Aden after it was damaged by Houthi missiles.
And in November, the rebels seized the vehicle transporter Galaxy Leader and its crew after boarding it via helicopter.
The Houthi attacks have prompted some shipping companies to detour around southern Africa to avoid the Red Sea route, which normally carries about 12 percent of global trade.
Their campaign has also triggered the formation of an international naval coalition to protect the busy commercial route.