Yemen's Iran-backed Huthis launched several drones and two ballistic missiles on Friday, the US military said, after deadly overnight strikes by American and British forces prompted retaliatory threats from the rebels.

US Central Command (CENTCOM) said it intercepted four drones launched by the Huthis -- three over the Red Sea and another over the Gulf of Aden -- while a fifth drone crashed.

The Huthis also launched two anti-ship ballistic missiles, according to CENTCOM, which said no injuries or damage were reported from US, coalition or commercial ships.

Earlier on Friday, the Huthis had threatened to step up their attacks on Red Sea shipping after overnight strikes by the United States and Britain that the rebels said killed 16 people.

The toll announced by the Huthis, which AFP could not independently verify, would make the strikes some of the deadliest since the United States and Britain launched a campaign against the disruption of the vital trade route in January.

The rebels, who control much of Yemen, have carried out dozens of drone and missile attacks on ships since November, claiming solidarity with Palestinians over the Israel-Hamas war.

The Huthi attacks have forced commercial vessels to divert from the shipping route, which normally carries about 12 percent of global trade.