ERBIL, Kurdistan Region of Iraq – Yemen’s armed forces on Friday said they were investigating reports that the Houthi rebels had used shells suspected to contain toxic substances in the southwestern Taiz province, with people allegedly suffocating and fainting from the projectiles' contents.

The army said it had received field reports from the Taiz front lines that the Houthis had used “shells suspected of containing toxic substances,” which had caused “suffocation and fainting.”

It called for an “urgent” investigation to determine the substances used, document their effects, and find those supplying them.

The reports come amid “sniper operations, indiscriminate shelling of residential neighborhoods, a suffocating siege of the city, and the cutting off of roads and prevention of access to water, food, medicine, and life-saving materials for millions of citizens,” the military said.

“The Armed Forces warn the Houthi militia against persisting in targeting civilians or using any prohibited weapons,” it added.

The military also called on the United Nations and other relevant international bodies to support the investigations into war crimes by the Houthis and to press for the opening of humanitarian aid routes.

While Yemen’s government controls the center of Taiz, the Houthi siege has made it difficult for supplies to reach them. Government forces have tried to repel the Houthis from the surrounding hills but face heavy resistance.

Gaining control of the strategic Taiz is vital for the Houthis if they want to advance further south towards Aden and Lahj, according to analysts.

Amnesty International has called on the Houthis to open the roads into Taiz, saying the city is being pushed to “the brink of a severe humanitarian disaster,” as water and fuel have become scarce.

The conflict between Riyadh and the Houthis had lain largely dormant since a UN-brokered ceasefire in 2022. However, the Iran-backed group blamed Saudi Arabia for an airstrike on Sanaa International Airport in July, setting in motion a chain of events that culminated in a large-scale Houthi offensive that expanded their effective control over war-wracked Yemen.

The rebels have amped up attacks deep inside Saudi Arabia, with attacks on airports, energy infrastructure, and pipelines.