The five fishermen were arrested in 2011.
Five Indian fishermen from Tamil Nadu have been given death sentence by a Sri Lankan court on charges of drug peddling. The men have 15 days in which to appeal against the order in a higher court. Both the Central and state governments say they will continue to fight the case.
The men, who are from a village in Rameswaram, had been arrested in 2011 on charges of carrying drugs into Sri Lanka.
India has been tracking the case since the arrest, said Syed Akbaruddin, spokesperson of the Ministry of External Affairs. The Indian High Commission in Sri Lanka has been assisting the fishermen with legal aid.
"We feel the fishermen are not guilty. We will follow the legal process and will do our best to get them back to India," he said.
But in Tamil Nadu, political parties criticised the Centre for doing little. "I don't think Indian government did anything significant," said DMK spokesperson TKS Elangovan.
In Rameswaram, the hometown of the five men, tempers ran high. Hundreds of fishermen hit the streets, blocking road and rail traffic. A bus was set on fire near Pamban and three trains bound for Chennai and Madurai were stranded.
The arrest of fishermen has long been an issue in Tamil Nadu. And the sentence comes at a time when the state is demanding the return of Katchatheevu, an island India had gifted to Sri Lanka in the early seventies. Former Tamil Nadu Chief Minister J Jayalalithaa has filed a petition in the Supreme Court in this regard.
Some headway was made on the arrests during the visit of Sri Lankan President Mahinda Rajapaksa in May for the swearing-in of Prime Minister Narendra Modi. A month later, Ms Jayalalithaa, who had boycotted the swearing-in to protest the invitation to Mr Rajapaksa, wrote to the Prime Minister, asking him to make the issue a priority.
Mr Rajapaksa ordered the release of a few hundred fishermen arrested for trespass. But those accused of drug peddling were not allowed to go.