Tamil Nadu Chief Minister M Karunanidhi yesterday sought a Central Bureau of Investigation (CBI) probe into the attack on a newspaper office in Madurai by supporters of his son Azhagiri that left three people dead.

Angry mobs set on fire the office of the Dinakaran paper Wednesday after the newspaper published a poll favouring Karunanidhi’s younger son Stalin over the elder Azhagiri as his political heir.

The chief minister told the assembly that as the violence was allegedly due to the fraternal feud in his family, it would not be right to have an inquiry by the state police.

“A CBI probe has been sought,” he said. The mayhem in the temple town of Madurai and neighbouring regions also led to the arrest of Mayor Thenmozhi’s husband Gopinath along with three members of the ruling DMK. All the DMK functionaries arrested were Azhagiri supporters.

It was all quiet Thursday with the government stepping up security in the district. Security has also been provided at the Dinakaran offices in Madurai and Chennai.

Police had arrested three dozen people late on Wednesday in several districts for arson, roadblocks and destruction of public property, including state transport buses and private vehicles.

Among those arrested was Azhagiri supporter and local goon Tiger Pandi.

The Azhagiri supporters who attacked the Dinakaran office, owned by the Sun Group, were led by the mayor. The Dinakaran has filed a police complaint and has demanded the arrest of Azhagiri, a powerbroker in the southern districts of Tamil Nadu.

Wednesday’s factional feud erupted just as the DMK was getting ready to celebrate. There was melodrama, malice and media machination.

Two pairs of siblings in the family, the Maran brothers and the Karunanidhi sons are involved, providing the right amount of tragedy for the chief minister and his party. On May 13, the DMK, led by 84-year-old patriarch M Karunanidhi, will complete one year of its rule in Tamil Nadu.

The party had also earmarked grand plans for tomorrow to mark — in a grand public function — its fifth-time Chief Minister Karunanidhi’s 50 years in the assembly.

On Friday evening, Karunanidhi’s coalition partners, Prime Minister Mammohan Singh, Congress president Sonia Gandhi,Nationalist Congress Party chief Sharad Pawar, Rashtriya Janata Dal supremo Lalu Yadav, Communist Party of India-Marxist leader Prakash Karat, Communist Party of India leader A B Bardhan, PMK’s S Ramadoss and many others will be on stage at Chennai’s Island Grounds to facilitate the “Kalaignar”.