At least 28 people were killed and 20 injured in two separate attacks by terrorists in Tripura on the eve of Independence Day on Thursday.

All Tripura Tiger Force terrorists attacked West Tripura district's Totabari village at around 2000 IST, killing six people instantly and wounding 14.

Of the 14, seven succumbed to their injuries on the way to hospital, sources said.

Nearly one-and-a-half-hour later, another ATTF group mowed down 12 people at Baralunga village and injured as many.

Three of the injured died later, the sources said.

Four Border Security Force jawans were injured at Khantlang, bordering Bangladesh, when suspected terrorists of the banned National Liberation Front of Tripura opened fire on them.

The jawans retaliated and the encounter lasted about 15 minutes. Reinforcements were rushed to the spot.

A group of NLFT terrorists fired at a police patrol at Kaptali in South Tripura district.