Thiruvananthapuram : The Kerala Police on Monday took into custody nearly 20 activists of the Youth Congress for allegedly attempting to show black flags to the convoy of Karnataka Chief Minister B S Yediyurappa here.

The activists were protesting against the recent “illegal” detention of Kerala journalists at Mangalore when they went to cover death of two persons in suspected police firing during the protest over the controversial amended Citizenship Act.

Yediyurappa, who reached the International Airport in the evening, was in the town on a personal visit.

“We apprehended the activists before they could show black flags. The chief minister will leave the town tomorrow,” police said.

The youth activists of the Congress were detained when they were attempting to show black flags to the Karnataka chief minister while he was on the way back from Padmanabhaswami temple.

The state has been witnessing widespread protests over the Citizenship Amendment Act.