RIYADH: UN inspectors have unearthed fresh evidence that Iran had undertaken work on nuclear weapons without declaring such activities, the Wall Street Journal reported on Saturday. "Samples taken from two sites during inspections in the fall by the U.N.’s International Atomic Energy Agency (IAEA) contained traces of radioactive material," the report said, quoting diplomats briefed on the discovery. While the diplomats said they didn’t know the exact nature of what was found, the discovery raises new questions about the scope of Iran’s nuclear ambitions, it added. Tehran has repeatedly asserted that its nuclear program was for peaceful purposes such as generating energy, but it has blocked IAEA inspectors from checking suspected sites. It has increased its nuclear activities after former US President Donald Trumped pulled his country out of the 2015 nuclear deal Iran signed with the US, European Union, Russia and China. Iran"s nuclear ambitions is being opposed by its Arab neighbors as well as by Israel, citing its record as a trouble-maker. It has been accused of supporting militias such as the Houthis in Yemen, the Hezbollah in Lebanon and others in Iraq and the Palestinian territories.