Dubbing the stabbing of a 21-year-old woman teacher in New Delhi as a "horrible" incident, megastar Amitabh Bachchan on Wednesday emphasised that society has to change.

"I have seen that video... It's a bad incident. Society has to change. We have to keep trying. Everybody just says that 'this is not my job and I am not interested in it'," he noted.

"A lot of people are afraid to help somebody because they feel they will be victimised in the police station. They don't want to get involved," Bachchan said here at a promotional for "Pink".

The woman named Karuna, of Burari area in north Delhi, was a teacher at Novel Reaches School. She was on Tuesday morning fatally stabbed as many as 22 times by her "jilted" lover.

However, Amitabh noted that society is "slowly" transforming and the laws are changing as well.

"But all these things are changing. The law is changing. I think people, when the moment they see some disaster, they are not liable to be questioned, if they bring that person either to the hospital or the police station," he said.

"When something happens on the road, most of the time people just drive past because they feel scared. But now there is a lot of understanding and laws are also changing," he added.