An RSS leader was on Monday attacked and injured allegedly by CPI-M activists at Kankol in Payanoor in Kannur district, police said.
He has been admitted to a hospital here and his condition is stated to be serious, they said.
RSS alleged that a group of CPI-M workers attacked Ajit with iron rods when a meeting of the saffron organisation was in progress late in the evening.
The district has been witnessing a spat of clashes between CPI-M and RSS-BJP workers after the May 16 Assembly polls which saw the CPI-M-led LDF government coming to power in the state.
In another incident, a 64-year-old Congress worker was attacked and injured allegedly by RSS-BJP workers at Panoor in the district.
The injured, M Sukumaran, a former school teacher, has been admitted to Thalassery Indira Gandhi Cooperative hospital, police said.
He was attacked while he was opening his shop in the morning.
Meanwhile, in the southern part of the state, a flag and flagpost of CPI-M was damaged allegedly by RSS-BJP workers at Paravoor in Kollam district.
On January 18, a 53-year-old BJP worker was stabbed to death at Andaloor in Dharmadam, the constituency of chief minister Pinarayi Vijayan.
Six CPI(M)workers have been arrested in this connection.
On Friday last, 10 people, belonging to BJP-RSS, were taken into custody here in connection with the hurling of a bomb near the venue of a public meeting of CPI(M) state secretary Kodiyeri Balakrishnan, police said.