A Yemeni rebel attack on a civilian airport in southern Saudi Arabia wounded nine civilians on Tuesday, a Riyadh-led coalition said, the latest in a series of strikes on the site.

“The terrorist attack on Abha airport... led to the injury of nine civilians, including eight Saudi citizens and one carrying an Indian passport,” the military coalition said in a statement carried by the official Saudi Press Agency.

Earlier, the Houthi rebels said they “launched a wide operation targeting warplanes at Abha international airport” with drones, according to their Al-Masira television channel.

The rebels in neighbouring Yemen — who have faced persistent coalition bombing since March 2015 which has exacted a heavy civilian death toll — have stepped up missile and drone attacks across the border in recent weeks.

On June 12, a rebel missile attack on Abha airport wounded 26 civilians, drawing promises of “stern action” from the coalition. On June 23, another rebel attack on Abha airport killed a Syrian national and wounded 21 other civilians, according to the coalition.

The Houthi said on Tuesday they will “not hesitate” to launch operations against Saudi Arabia and the coalition, adding they have a new missile system. “Our forces are capable of targeting a number of targets simultaneously and with different weapons,” said a Huthi spokesman during a televised press conference.

He said targets include oil pipelines and facilities.

The raids come amid heightened regional tensions after Washington — a key ally of Riyadh — accused Iran of shooting down a US drone over international waters and of carrying out attacks on oil tankers in the strategic Gulf of Oman.

Saudi Arabia has repeatedly accused Iran of supplying sophisticated weapons to Houthi rebels, a charge Tehran denies.

Following recent attacks, Saudi state media have reported an intensification of coalition air raids on rebel positions in the northern Yemeni province of Hajjah and the Huthi-held capital Sanaa.

The coalition intervened in support of the Yemeni government in 2015 when President Abedrabbo Mansour Hadi fled into Saudi exile as the rebels closed in on his last remaining territory in and around the second city Aden.

Since then, the conflict has killed tens of thousands of people, many of them civilians, relief agencies say. The fighting has triggered what the United Nations describes as the world's worst humanitarian crisis, with millions of people displaced and in need of aid.