Police and Interior Ministry troops armed with rubber truncheons and backed by water cannons prevented several thousand opposition protesters from approaching the presidential palace in Yerevan on 18 March, RFE/RL\'s Yerevan bureau reported. The demonstrators were protesting the 15 March arrest, which they consider politically motivated, of businessman Armen Sargsian on suspicion of having commissioned the 28 December slaying of Armenian National Television and Radio head Tigran Naghdalian. Sargsian\'s lawyer, Robert Grigorian, told RFE/RL that the charges against Sargsian should be dropped because of a lack of evidence. Sargsian\'s mother, Greta, who picketed the presidential palace on 17 and 18 March, said her son is innocent and should be released on bail. (RFE/RL)