The city police had arrested five persons–four from Chennai- from the city railway station on September two on suspicion that they had come with a plot to kill Arjun Sampath, president of Hindu Makkal Katchi. Later two more persons were arrested for allegedly giving the shelter and transport.As they were booked under various sections including 143 and 120 B (conspiracy) and also to incite communal clash, the case was handed over to NIA and some officials reached the city this morning and carried out search in the houses of Faisal in Ukkadam, Ashiq in Chandran Street and Anwar of Kuniamuthur, police said.