Four workers of the Rashtriya Swayamsevak Sangh were arrested on Sunday for allegedly stabbing four activists of the Students’ Federation of India in Kannur earlier in the day, The New Indian Express reported.

Kannur district has been the hotbed of political violence between Left- and Right-wing groups for years. The Students’ Federation of India is the student wing of the Communist Party of India (Marxist).

The SFI workers – three of them 19 and the fourth 18 years old – were returning home after a temple festival when the RSS workers allegedly attacked them around 3 am on Sunday. One of them is in critical condition and is under intensive care.

The Taliparamba Police filed cases against the four RSS workers for attempt to murder. They identified the attackers using footage from the temple’s CCTV cameras. Ten more suspects may be arrested, the police told The New Indian Express.

Those arrested were allegedly also involved in a clash at a bar in Pazhayangadi town on Saturday night, the police said.

The district leadership of the Bharatiya Janata Party condemned the attack.