South Korean police said Monday they have rounded up 15,617 gangsters, burglars, pickpockets and other criminals in a crackdown ordered to ensure the safety of the Summer Olympics in Seoul. Since the crackdown began on June 27 police have brought formal charges against 3,720, with the remaining suspects under investigation or sent to summary court trials charged with minor offenses. Police said about 100,000 security personnel were mobilized in the crackdown, which they said will remain in effect until the Olympics, which begin on Sept. 17.