Cairo - A leading rights group has called the recent drone attack by Yemen’s Al Houthi militia on an airport in Saudi Arabia an “apparent war crime”.

Human Rights Watch urged Al Houthis to stop attacks on civilian infrastructure in Saudi Arabia. Al Houthi attack on the southwestern Saudi town of Abha’s regional airport wounded 26 people Wednesday.

The comments came as the coalition launched air strikes on Al Houthi forces in Sana’a, Saudi state television reported early on Saturday. The strikes hit air-defence systems and other military positions in the Al Houthi-controlled city, according to the TV report.

The coalition has been battling Al Houthis in Yemen since 2015 to try to restore the internationally recognised government that was forced out of Sana’a by the militia.

Al Houthis have stepped up drone and missile attacks on cities in Saudi Arabia in recent months as tensions have risen between Iran and Gulf states further afield across the Middle East.

Yemen’s civil war has killed more than 10,000 people and pushed the impoverished country to the verge of famine, the United Nations and aid agencies have said.

Saudi Arabia said the Al Houthi attack on Abha airport on Wednesday wounded 26 people.

The escalation in violence could threaten a fragile UN-led peace initiative in Yemen’s main port city of Hodeida, which handles the bulk of the country’s commercial and aid imports and is a lifeline for millions of Yemenis.