U.S. Ambassador to the United Nations Nikki Haley said Thursday that she had “undeniable” evidence that Iran has been funneling missiles to Houthi rebels in Yemen in violation of U.N. resolutions.

The evidence Haley unveiled included segments of missiles launched at Saudi Arabia from Houthi-controlled territory in Yemen. She said the missile parts bear markings showing they originate in Iran and that they have technical specifications that are specific to Iranian-manufactured weapons.

“The evidence is undeniable,” Haley told reporters in a hangar at Joint Base Anacostia-Bolling in Washington. “The weapons might as well have had ‘Made in Iran’ stickers all over it.”

U.S. officials have long suspected Tehran of supporting the Shiite Houthis in Yemen, which has been locked in a vicious civil war since 2015. On Wednedsday, U.N. Secretary General Antonio Guterres said the world body was investigating Iran’s possible transfer of ballistic missiles that may have been used in launches aimed at Saudi Arabia on July 22 and Nov. 4.