Indore | A message claiming a bomb had been placed on Air India's flight from Delhi to Mumbai via Indore was posted on a social media platform which later turned out to be a hoax, police said on Wednesday.

The Indore police in Madhya Pradesh have registered a case in this connection against an unidentified person, they said.

The "threatening message" that a pipe bomb was placed in Air India's flight AI 636 was posted on an X social media account at 5.08 pm on Tuesday, an Aerodrome police station officer said quoting a complaint by a local official of the airline.

The flight, arriving from Delhi, had already left for Mumbai from Indore at 4.38 pm, he said.

"The message about a pipe bomb being placed in the Air India flight was proved to be fake in our investigation," Deputy Commissioner of Police Vinod Kumar Meena told PTI.

A case was registered against the unidentified person who posted the threatening message on social media under Bharatiya Nyaya Sanhita section 351 (4) (criminal intimidation by concealing identity), he said, adding that further investigation was underway.

More than 100 flights operated by various Indian airlines received bomb threats on Tuesday, according to sources.

In 16 days, more than 510 domestic and international flights have got the threats that later turned out to be hoaxes. The threats were issued mostly through social media.