A man who opened fire on Red Square during the Revolution Day parade has been charged with committing a terrorist act, a spokesman for the KGB secret police said Thursday. Alexander A. Shmonov, 38, of Leningrad, will undergo psychiatric tests to determine whether he was sane at the time of the shooting Wednesday, said Alexei Kandaurov, deputy director of the KGB public relations office. He gave no other details on the case. No one was hurt in the incident, in which the man pulled out the hunting rifle in the heavily guarded square about 80 yards from President Mikhail S. Gorbachev. The shooting came during a Communist Party march that followed the military parade. A plainclothes officer knocked the weapon away as the man fired once into the air and again into the ground, newspapers said. He then was subdued by about 20 plainclothes officers and carried into the GUM department store across the square from Gorbachev. Foreign Minister Eduard A. Shevardnadze played down what may have been an assassination attempt, categorically denying that it indicated a loss of public support for Gorbachev's ``perestroika'' reform policies. ``I don't think this incident should be taken very seriously,'' Shevardnadze told reporters before meeting with visiting Secretary of State James A. Baker III. ``This is a huge country where something is always happening somewhere.'' Shmonov was interrogated and spoke in detail about his preparations for the act, the official Tass news agency quoted KGB investigator Pyotr Sokolov as saying. Soviet Deputy Prosecutor Janis Dzenitis on Thursday sanctioned Shmonov's arrest, Tass reported. Shomonov is charged with committing ``an attempted terrorist act,'' the news agency quoted Sokolov as saying. Kandaurov could not confirm a report by one newspaper that the gunman was carrying a light explosive in addition to the rifle. The conservative labor newspaper Trud said Shmonov was carrying a small explosive usually used for military rehearsals that could cause no serious damage. Kandaurov said the man was carrying at least one device, but added that laboratory tests would have to confirm whether it was an explosive. ``It is hard to tell now whom he was aiming at,'' Trud said. ``But one thing is clear: If it were not for the immediate reaction of a policeman, who succeeded in knocking the gun into the air, a disaster might have happened.'' KGB chief Vladimir Kryuchkov indicated Wednesday night that officials believed the man was deranged. Shmonov is being held in the KGB's isolation ward, Tass reported. Shmonov is an unemployed metal craftsman who last worked at the Izhorsky metal working factory in Leningrad, Kandaurov said. Soviet newspapers on Thursday carried front-page pictures of the gunman being subdued by plainclothes security. Newspapers were filled with glowing reports about the celebrations across the country Wednesday, the 73rd anniversary of the Bolshevik Revolution. There were only brief reports about anti-Gorbachev rallies by hard-liners and radicals, which the Communist Party newspaper Pravda criticized as ``extravagant escapades verging on simple hooliganism.''