All of the injured have been admitted to hospital. (File photo: Reuters)

RSS workers and activists from a Communist youth group were injured when they clashed in Thiruvananthapuram, Kerala's capital, on Wednesday night.

Four people were involved in the clash -- two each from the Rashtriya Swayamsevak Sangh and the Democratic Youth Federation of India (DYFI).

The incident happened near Thiruvananthapuram's Petta area.

The RSS workers -- Shaji and Shyam -- were allegedly attacked with sharp objects.

The police have registered a case against the DYFI activists.

While Shaji and Shyam were admitted to the Thiruvananthapuram Medical College, the DYFI activists were admitted to the city's General Hospital.

An investigation is ongoing.