Three persons were killed on Friday morning in two different incidents of gaur attack at Erumeli and Anchal in Kottayam and Kollam districts respectively, police said. Chackochan (70) and Thomas (71) were killed at Erumely after a gaur, which ventured into a rubber plantation near here, attacked them at around 8 AM. A senior forest official told PTI that Thomas, who was engaged in rubber tapping inside the plantation which was near the forest area, was attacked first by the gaur.