Prime Minister Narendra Modi arrived in Chennai on Thursday morning to inaugurate Defence Expo India 2018 amid demonstrations against the Centre’s delay in forming the Cauvery Management Board. Fifty Dravida Munnetra Kazhagam workers were arrested as they waved black flags, The Hindu reported.

Modi is also observing a day-long fast on Thursday, along with other Bharatiya Janata Party MPs, to mark their protest against the deadlock in Parliament during the recently-concluded Budget session.

Workers of the Marumalarchi Dravida Munnetra Kazhagam, including party chief Vaiko, protested outside the Raj Bhavan with black flags and balloons, ANI reported. Some cadres of the Tamizhaga Vazhvurimai Katchi climbed up a hoarding near the Chennai airport and waved black flags.

Amid tight security, the prime minister travelled by helicopter from the airport to Mahabalipuram, and then to the exhibition venue in Thiruvidanthai by road at 10.15 am. A three-tier security system had been arranged at the airport, and at places where Modi is scheduled to go after the exhibition, reported The New Indian Express.

Modi will not travel by road till he leaves Chennai at 2.30 pm, according to The Hindu. A helicopter carrying him will land on a cricket ground at the Indian Institute of Technology, Madras, where he is scheduled to go after inaugurating the Defence Expo.

Traffic police have blocked some routes for security reasons. Protestors wearing black T-shirts and waving black flags had blocked traffic on the roads leading up to the Chennai International Airport, in Guindy in south west Chennai, earlier in the day.

The Dravida Munnetra Kazhagam released a picture of its president, M Karunanidhi, wearing black as a mark of protest against Modi’s visit. The party had announced on April 1 that its workers would wave black flags at Modi.

The Defence Expo is a four-day exhibition showcasing the country’s latest weapons and defence manufacturing capabilities. Defence Minister Nirmala Sitharaman was also present at the event.