New Delhi, May 26 -- In a special operation in West Bengal's Malda district, the National Investigation Agency (NIA) on Monday arrested 15 protestors in connection with last month's road blockades and illegal detention of judges engaged in a Special Intensive Revision (SIR) exercise of electoral rolls ahead of the Assembly elections in the state.

NIA, which had taken over the investigation on the Election Commission of India's direction after the Supreme Court took suo moto cognisance of the acts, carried out an extensive operation in Malda district yesterday.

A total of 15 persons were apprehended for their involvement in the blockade of roads and the illegal detention of judicial officers on duty in two separate cases.

In one case, 1...