Iran-backed Houthi militants in Yemen say they carried out drone and missile attacks on the Saudi capital Riyadh and energy sites on the country’s Red Sea coast.

A column of black smoke was seen rising from what appeared to be fuel tanks near the Saudi capital’s international airport on Saturday, hours after air raid alerts were issued.

It was the first time residents had been given an alert and urged to stay indoors since a recent escalation in the conflict with the Houthis.

There has been no official comment from Saudi authorities.

In a statement posted online, Houthi military spokesman Yahya al-Sarea said a “large number of ballistic and cruise missiles and drones” had been used to attack “sensitive sites” in Riyadh and Aramco state oil and gas company facilities in Yanbu on the coast.

He added that the attacks were “in response to the Saudi enemy’s criminal attempts” to target the Yemeni capital Sanaa.

Earlier, Sarea had accused Saudi Arabia of carrying out 300 strikes across Yemen during the past week.

The Houthis are locked in a civil war with Yemen’s internationally recognised government, which is backed by Saudi Arabia.

They have attacked targets inside Saudi Arabia on several occasions in recent months, and said this week that they were responsible for downing a Saudi fighter jet over Yemen.

According to an unconfirmed report from AFP news agency, quoting military sources on both sides of Yemen’s civil war, fighting between the Houthis and Saudi-backed government forces claimed 48 lives on Saturday.

The Houthis said 31 of their fighters had been killed while government sources said their side had lost 17 soldiers, according to the news agency.

On Friday, the International Organization for Migration, a UN body, reported that the number of people displaced as a result of recent fighting had passed 104,796, external.