The arrested men were among the eight persons identified as accused in the case.
Four RSS activists have been arrested in Kannur today in connection with the July 11 murder of a 38-year old CPM worker over political rivalry in the politically volatile Payyannur district, police said.
A team led by Payyannur Circle Inspector V Ramesh arrested Vysakh, 21, Sukesh, 29, Prejithlal, 21, and Anoop, 21, all hailing from the district, they said.
The arrested men were among the eight persons identified as accused in the case. The four allegedly had direct involvement in the crime and the others will also be nabbed soon, police said.
CV Dhanaraj was hacked to death by a group of people, allegedly RSS activists, when he was entering his house at Payyannur. He had died while being rushed to the hospital.
In a suspected retaliatory attack hours later, 52-year-old BJP activist Ramachandran, an autorickshaw driver, was murdered by another group at his house in Vellur village in the district, police said.
No arrests had been made so far in this connection.
Kannur and some parts of the state had witnessed clashes between CPM and BJP workers after the May 16 Assembly election results.