 But after an attempted assassination of the Shah in 1949, he was able to declare martial law, imprison communists and other opponents, and restrict criticism of the royal family in the press.Following the pro-Shah coup d'état that overthrew the Prime Minister Mohammad Mosaddegh in 1953, the Shah again cracked down on his opponents, and political freedom waned.He outlawed Mosaddegh's political group the National Front, and arrested most of its leaders.