Around 100 prisoners took part in the strike, Xinhua news agency quoted prisons department officials as saying.
The prisoners called for a pardon and refused to suspend the fast till they get an acceptable solution.
Sri Lanka’s opposition leaders and Tamil political groups have called for the release of all Tamil political prisoners.
Opposition MPs say at least 300 political prisoners remain jailed in the island nation.
The Sri Lankan military crushed the Liberation Tigers of Tamil Eelam (LTTE) in 2009, after which hundreds of guerrillas and sympathizers were taken into custody. Most them have been freed. (New Indian Express)