The 150-strong team of police and forest personnel tried to get the animal under control at Kothagiri, about 40 km from here. The bear had recently killed a woman, forest officials said.
Police fired at the bear after it attacked three personnel when they approached with a net to capture it, assuming it had been immobilised by the tranquiliser, forest officials said.
The joint team, which included the Special Task Force police personnel, tried to capture the animal, which had recently killed a 45-year-old woman, and injured her husband and two sons at Thottamokkai village near Kothagiri.
Assuming that it was tranquilised, some personnel went near the bear and attempted to spread a string net to catch it. However, it rared up suddenly and attacked the personnel, resulting in serious injuries to a bystander, forester and a police personnel.
At this, a police personnel fired at the bear, which killed it, Forest Department Veterinarian, Vijayaraghavan, who performed post-mortem on the animal, said.