A Youth Congress activist was held for waving black flag at Kerala Chief Minister Pinarayi Vijayan here on Saturday, police said.

He showed the black flag and raised slogans against the government when the Chief Minister's convoy passed through Chalissery in Palakkad district to attend a programme.

Police soon arrested and removed him from the place.

In the wake of the Chief Minister's visit, security was beefed up in many parts of the district considering the ongoing protests by opposition parties against the state budget proposals.

Four Youth Congress activists were placed under preventive detention earlier in the day in Chalissery, police said.

They were released after the scheduled programme of the Chief Minister ended, they added.

Last week, Youth Congress workers had waved black flags at Vijayan at multiple locations in Ernakulam district as part of their protest against the state government's refusal to roll back the budget proposals to levy cess on fuel.