Thailand and Cambodia exchanged fire on Tuesday, with the Thai army accusing its neighbour of violating a truce reached in December after weeks of conflict.According to the Thai media’s statement quoted by news agency AFP, the Cambodian forces fired a single 40 mm grenade round” near a Thai patrol in the border province of Sisaket on Tuesday morning, prompting return fire.“Following the incident, Thai forces responded by firing an M79 (grenade launcher) in the direction from which the shot originated, in accordance with the rules of engagement, as a warning and for self-defence,” it added.“Preliminary assessment suggests the incident may have resulted from a rotation of Cambodian troops, with new personnel lacking familiarity with regulations and command control, leading to operational shortcomings,” the statement further said.The two countries have a centuries-old border conflict stemming from a French colonial-era demarcation of their 800-kilometre (500-mile) frontier.Dozens of people, including soldiers and civilians were killed, and a million others were displaced in last year’s conflict.