A police official said the wild bear attacked the people near a school at Chorda locality here around 6 am injuring four persons, a woman among them.
It pounced mainly on the passers-by and morning-walkers. Locals later retaliated by pelting stones at the bear.
In a bid to escape, the bear started running and fell into a drain near the old police station and remains trapped in it, Cuttack DFO Sudarshan Behera said.
Experts from Nandankanan Zoo were called in to rescue the trapped animal, Behera said.
"We have sealed the drain from both the side by fencing and our rescue operation is still on," he said.
The injured people have been taken to a hospital at the Jajpur Road.