THIRUVANANTHAPURAM: Entry of women of menstrual age sparked violent protests across Kerala by the BJP and Hindu right outfits, with the state secretariat turning into a veritable war zone for nearly five hours as the ruling CPI(M) and workers of the saffron party clashed, pelting each other with stones.

Police used water canons and burst teargas shells to bring the situation under control.

Chief Minister Pinarayi Vijayan's effigy was burnt at Malappuram and four activists of the BJP's Mahila Morcha were arrested when they forced their way close to the chief minister's office in the secretariat complex.

As the news spread like wildfire from the hill shrine, protests erupted at several places, with Hindu right-wing activists blocking highways and forcing closure of shops and markets.

The ruling CPI(M)'s offices were vandalised at several places causing tension, police said.

State-owned KSRTC buses were damaged at Konni and Kozhencherry in Pathanamthitta district where the temple is located besides several other places. Devaswom Board offices attached to temples across the state were also locked up.

Several policemen were injured in the violence.

People from media were also attacked by BJP activists in front of the secretariat, officials said.

Sabarimala Karma Samithi, an umbrella organisation of various pro-Hindutva groups, spearheading protests against the Supreme Court's September 28 verdict, and Antarrashtriya Hindu Parishad (AHP), have called a state-wide shutdown on Thursday, when the Congress-led UDF said it would observe a "black day".

Soon after some local TV news channels aired visuals of the two women trekking to the hilltop temple, Chief Minister Piranayi Vijayan, whose Left Front government is weathering a storm of protests by hardline Ayyappa devotees over his determination to enforce the apex court verdict, announced they had indeed offered prayers at the shrine.