At least seven Congress workers, including a KPCC secretary, were taken into preventive detention ahead of Prime Minister Narendra Modi's visit to this port city on Monday, police said. District Congress Committee (DCC) President Muhammed Shiyas confirmed that seven Congress workers from the Western Kochi area were taken into preventive detention by the police in the early hours of Monday. They include KPCC secretary Thampi Subrahmanyam and DCC secretary Sreekumar, they said.