The clash took place at a time when Kerala is gearing up for the May 16 polls, which is expected to see the BJP, which is yet to open its account in the state, giving a tough fight to both ruling Congress-led UDF and CPI(M)-led LDF.
At least 16 persons sustained injuries, including former BJP state president, V Muraleedharan and some police personnel in the clash last night.
Shops and commercial establishments in various parts of the district have downed shutters, with vehicles being exempted from the hartal's purview in view of the SSLC, CBSE and various other examinations.
Later at night, the workers of both the parties again clashed at Kattayikonam.
Police jeeps and shops were damaged in stone pelting.
While the BJP has called for a 12 hour hartal from 9 AM to 6 PM in Thiruvananthapuram district, the CPI(M) hartal is restricted to Kazhakootam and Kattayikonam.