A 40-year-old man was hacked to death and two others were injured allegedly by some unidentified in a running bus in Tamil Nadu on Sunday night, triggering tension.

Mandiram, a Dalit, and two others of Kothakulam village, about 15 km from here, were returning home in a state-owned transport corporation bus when unidentified persons, also travelling in the same vehicle, suddenly attacked them with sharp edged weapons near Muneerpallam around 9.30 PM much to the shock of co-passengers, police said.

Mandiram died in the bus itself while the two others suffered injuries and had been admitted to the Government Medical College Hospital here, they said adding the assailants escaped.Police said they suspect previous caste-based enmity to be behind the attack, which sparked tension in the area.

Police personnel have been posted in Kothakulam and Tirunelveli Superintendent of Police Narendran Nair was camping in the area, they said.