Thrissur: A protest by the Congress-led UDF turned violent as activists clashed with police over toll collection at an NHAI toll plaza in Nattika here on Thursday, police said.

The National Highways Authority of India (NHAI) has decided to start toll collection at Nattika on NH 66 from October 8.

However, UDF leaders alleged that toll collection had started without completing the works on the service road and pedestrian overbridges, officials said.

At around 7.30 am, Congress and Indian Union Muslim League (IUML) activists marched to the toll plaza before toll collection commenced.

When they attempted to block the toll plaza operations, police intervened, leading to an altercation, officials said.

Police arrested and removed some of the protesters.

However, more UDF leaders assembled at the site, alleging that some of the activists had been manhandled by police, officials said.

Officials said that some of the policemen were injured following the clash.

A large number of police personnel are currently deployed at the toll plaza to prevent any further violent protests.

The LDF has also announced a protest march against the toll collection on Thursday, police added.