New Delhi, May 17 -- The Election Commission of India (ECI) has launched an investigation following the arrest of 25 foreign nationals for allegedly casting votes in the April 23 Tamil Nadu assembly elections, senior ECI officials said on Saturday. According to officials, the arrests occurred at Chennai and Madurai airports as the accused were preparing to board flights out of the country. The accused were intercepted between May 7 and 14 after immigration officials noticed indelible ink marks on the fingers of passengers carrying foreign passports. Nationals from Sri Lanka, the United Kingdom, Canada and Indonesia were among those arrested. "They had used fraudulent Indian ID documents to cast the votes. The indelible ink was noticed on th...