Three persons were arrested with the Colombo Central Mail Exchange today with 600 letters defaming President Maithripala Sirisena and causing racial disharmony. 

The three persons are believed to be close associates of a senior Cabinet minister representing the Kandy district. 

Police said the postal department officials examined their package as it looked suspicious. 

Upon finding the defamatory letters, the officials contacted the Fort Police Station which subsequently arrested the three individuals.