"The heroes of the Royal Air Force were able to successfully target the leader of the Huthi militia Saleh al-Sammad," Saudi Arabia's ambassador to the United States, Prince Khaled bin Salman, tweeted late Tuesday.

Sammad, head of the Huthis' supreme political council, was killed Thursday in the western province of Hodeida, the Iran-allied rebels said.

The Huthis are battling the Saudi-backed Yemeni government -- and a military coalition spearheaded by Riyadh -- for control of the impoverished country.

Prince Khaled said the strike was overseen by his brother, Crown Prince Mohammed bin Salman, after Sammad threatened a wave of missile strikes against Saudi Arabia.

Prince Mohammed, who is also the Saudi defence minister, has been the driving force behind Riyadh's intervention in the devastating Yemen war.

The conflict has claimed nearly 10,000 lives in three years and pushed Yemen to the brink of famine.

Sammad is the most senior Huthi leader to have been killed since the coalition intervened in March 2015 and his death is a major blow to the Shiite rebels.

The killing sparked threats of revenge by rebel chief Abdul Malek al-Huthi on Monday, who warned the "crime" would not "go unanswered".

The Huthis have this year regularly launched ballistic missiles into Saudi Arabia, which shares a land border with northern Yemen. One person has been killed in the attacks.

Ports in Yemen, which is dependent on food imports for the survival of the population, remain blockaded by the Saudi-led coalition in retaliation for the missile strikes.

The United Nations has called the Yemen war the world's largest humanitarian catastrophe.