Houthi rebel forces killed over 80 Saudi-led troops, including 42 Blackwater mercenaries, in a ballistic missile attack in the western Bab-el-Mandeb area.

The Yemeni army, backed by popular committees loyal to the Houthi rebel movement, targeted a Saudi military headquarters in the Yemen’s southwestern province of Ta’izz with a Tochka ballistic missile on Sunday night, Yemen’s Arabic-language al-Masirah news website reported.

Twenty-three Saudi, nine Emirati, and seven Moroccan forces, including a number of commanders, were also killed in the attack. Other reports said the attack left nearly 150 casualties among the Saudi-led forces.

The surface-to-surface missile also destroyed two Patriot missile systems, three Apache helicopters,more than 50 military vehicles, all belonging to the US Blackwater Worldwide security services company. The report added that two Saudi warships were damaged while fleeing the incoming Katyusha rockets that were fired spontaneously due to the missile impact.

Elsewhere, a Yemeni ballistic missile, named Qaher 1, hit a regional airport in the Saudi region of Jizan. There were no immediate reports of possible casualties and the extent of damage inflicted.

Meanwhile, a Yemeni army spokesman said the forces killed some 20 Sudanese mercenaries in an attack on Yemen’s southwestern province of Lahij.

Yemenis carry out these attacks in retaliation for Saudi strikes, launched with the aim of bringing back to power the country’s embattled president, Abd Rabbuh Mansur Hadi, a staunch ally of Riyadh.

More than 7,500 people have been killed and over 14,000 others injured since the strikes began. The Saudi war has also taken a heavy toll on the impoverished country’s facilities and infrastructure.

On Friday, Amnesty International slammed Saudi Arabia’s deliberate strikes on schools in Yemen as war crimes, calling for the prosecution of those involved in the attacks.

The International Committee of the Red Cross in Yemen also warned of a humanitarian catastrophe in the country, documenting over 100 airborne attacks on hospitals since March. It warned that that hospitals and healthcare facilities are no longer safe places for people.