A senior ranking officer in the Lebanese army was arrested on Tuesday on suspicion of spying for Israel, authorities said. A colonel was detained last week and was now being investigated by authorities over his possible connection to Israeli espionage services. The latest arrest follows a wide-scale move by authorities to close in on an alleged ring of Lebanese citizens who are accused of spying for Israel. Also Tuesday, state-run National News Agency said military prosecutor Saqr Saqr charged three people with collaborating with Israel. Fifteen members of the alleged ring, including retired Lebanese general Adib Alam, were recently arrested by Lebanese authorities on suspicion of passing information to Israel. As many as 30 suspects are being held in connection to the investigation and more than 20 have already been charged. Last Monday, two Lebanese citizens suspected of spying for Israel fled the country and crossed the heavily fortified border into Israel. Brenda Gazzar and AP contributed to the report.