North Korea has been shipping supplies to the Syrian government that could be used to make chemical weapons, according to a shocking new report Tuesday morning from experts at the United Nations. The investigators’ report—which was obtained by The New York Times—said the supplies include acid-resistant tiles, valves, and thermometers, and goes on to claim that North Korean missile technicians have also been seen working at weapons facilities inside Syria. The report comes amid news that a chemical-weapons watchdog is investigating attacks in the besieged eastern Ghouta region of Syria to determine the veracity of reports of the Assad government’s repeated use of chlorine bombs this month. According to the Times, the U.N. report details 40 shipments of prohibited missile parts and materials from North Korea to Syria between 2012 and 2017. The report warns that such illicit trade between North Korea and Syria could allow Syria to maintain its chemical-weapons arsenal while also providing North Korea with money to advance its nuclear-weapons program.