SANTIAGO (Reuters) - A Pakistani man arrested at the US Embassy in Chile after triggering an explosive detector was charged on Saturday with illegal possession of explosives, but was freed pending a probe. The man, identified by the US State Department as 28-year-old Muhammad Saif-ur-Rehman Khan, was taken into custody at the embassy on Monday and held in a maximum security prison under an anti-terror law. He must sign in once a week with authorities and may not leave the country while the case is investigated, court officials said. Police said traces of the explosive Tetryl were found on Khans documents and mobile telephone. Tetryl is a compound used as a booster to help detonate explosive charges. He was basically (charged) for an infraction of the law on firearms and explosives, state prosecutor Xavier Armendariz told reporters after the hearing. The investigation is open and continues. A senior State Department official said on Tuesday that Khan, a student who had been in Chile for four months, was invited to the embassy so officials could notify him that his visa for the United States was being revoked. The US official, who spoke on condition of anonymity, said he was not aware of any link between Khan and the Pakistani-American accused of trying to bomb New Yorks Times Square on May 1. Khan has denied any wrongdoing and instead criticised the United States. I have nothing to do with bombs. I have nothing to do with terrorists. I dont have a beard, Khan told reporters on Tuesday evening. They (the United States) just want to cover up their shame and guilt for what they have done or are doing in Iraq and Afghanistan.