French airstrikes targeted and destroyed 12 buildings in Iraq Friday that Islamic State militants used to stockpile weapons, France’s Chief of Staff of Armed Forces Pierre de Villiers said. The bombing run was part of a larger coalition operation that dropped 70 bombs on targets affiliated with the group, formerly known as ISIS or ISIL.

“Tonight we undertook a big operation in Iraq in which we destroyed buildings in which Daesh (Islamic State) was producing traps, bombs, arms to attack the Iraqi forces,” de Villiers told Europe 1 radio, according to Reuters. The targeted buildings were completely neutralized, he said.

Galvanized by ISIS’ beheading of French citizen Herve Gourdel, France was the first nation in September to contribute to U.S.-led coalition airstrikes against the Islamic State, CNN reported. In addition to airstrikes, France has provided weapons to Kurdish peshmerga fighters in Iraq and helped to train Iraqi fighters.

De Villiers’ announcement came days after an Iraqi Defense Ministry official confirmed that Islamic State militants used chlorine gas to attack local police on Sept. 15, the Washington Post reports. Officials suspect that ISIS extremists have used chemical weapons on at least two other occasions.

“They use it just to create terror, the official said. “But of course we are very concerned.” The chlorine gas was used in a “primitive and ineffective way,” the Defense Ministry said in a statement.

The U.S. National Security Council said Thursday that officials are investigating the reports of chemical weapons use, but had yet to confirm the Iraqi government’s account. “We are aware of the reports but cannot confirm details and are seeking additional information,” council spokesman Alistair Baskey said. “The use of chlorine as a chemical weapon is an abhorrent act.  These recent allegations underscore the importance of our work to eliminate chemical weapons in this volatile region.”