His father and party founder Dr S Ramadoss was granted bail today. However, Ramadoss could not walk out of the prison at Tiruchirappally in view of other pending cases.
The PMK founder was arrested on April 30 for trying to stage a protest demanding arrest of "true culprits" behind the violence at Marakkanam in Villupuram district, allegedly targeted against Dalits.
Chief Minister J Jayalalithaa had blamed the party for the violence.
Anbumani, PMK Youth Wing Leader, was arrested from his T Nagar residence here by Kanchipuram police in connection with a case filed last year.
He was arrested under different sections including Unlawful Assembly, Activities prejudicial to Peace, Violation of Police Rules, and the offence of acting against General Public - under the Amended criminal Law.
Protests were held near Kanchipuram opposing Anbumani's arrest, which comes two days after police action against his father.
In the wake of the developments, some preventive arrests were made including in northern districts which has a sizeable population of Vanniyars, the community PMK claims to represent, police said.
However, no untoward incident was reported today, police added.
Violence had erupted following the arrest of Ramadoss on April 30, with many government buses being torched by miscreants.
The arrested PMK leaders found support from unexpected quarters with DMK chief M Karunanidhi seeking their release that had a word of caution.
Karunanidhi sought the release of Ramadoss on humane grounds even as the octogenarian leader asked his younger political colleague to refrain from making statements that were inappropriate in political context.
Terming the arrest as a repressive measure by the state government, he said the "Government should also stop its repressive measures. Those arrested (including Anbumani) must be released," he said.
Karunanidhi and Ramadoss had been at loggerheads ever since the two split up after the 2011 elections.
Meanwhile, PMK had called for a dawn-to-dusk bandh in the neighbouring Puducherry where private buses and autorickshaws laregly remained off the roads today.
Shops and establishments including retail outlets of the petroleum products remained closed but attendance in government offices was normal.