The civil aviation ministry plans to put in place strict norms to prevent incidents of hoax bomb threats to airlines, including placing the perpetrators on the no-fly list, a senior official said on Thursday.

In four days, more than 20 flights of various Indian airlines received bomb threats, including international flights, and some of them were diverted. Most of the threats have turned out to be hoaxes.

Against this backdrop, the ministry is looking at amending existing rules, including those related to the Bureau of Civil Aviation Security (BCAS), in order to ensure stringent punishments are in place for the culprits, the official in the know said.

Placing individuals making hoax bomb threats in the airlines' no-fly list is one of the proposals being looked at, the official said.

The official also said legal opinions are being gathered with respect to making the changes in the rules.

The provisions being followed in foreign countries to deal with hoax bomb threats are also being examined by the ministry.

Further, the official said that if necessary, legislative amendments will be explored for having a strong deterrent to prevent people from making hoax bomb threats to airlines.

Currently, there are strict norms against unruly passenger behaviour onboard flights but there are no specific provisions under the aviation regulations to deal with instances where a bomb threat has come from outside sources such as social media.

At present, the actions against hoax bomb threat incidents are taken by the police under criminal laws.

The official also said that discussions are going on with home and law ministries while inputs are being gathered from airlines.

"We want rules that can act as a deterrent," the official said.

On Wednesday, Civil Aviation Minister K Rammohan Naidu said law enforcement agencies are actively pursuing all cases of bomb threats against airlines and the government is closely monitoring the situation.

He also condemned any attempt to compromise the safety, security and operational integrity of the aviation sector.

Except for the headline, this story has not been edited by The Telegraph Online staff and has been published from a syndicated feed.