More than 20 flights of various Indian airlines have received bomb threats since Saturday morning, according to sources.

Flights of Air India, IndiGo, Akasa Air, Vistara, SpiceJet, Star Air and Alliance Air have received the threats, the sources said.

Among them are IndiGo's flights from Delhi and Mumbai to Istanbul, and Jodhpur to Delhi as well as Vistara's flight from Udaipur to Mumbai.

IndiGo, in two separate statements, said it is cognisant of a situation involving flight 6E 17 from Mumbai to Istanbul, and flight 6E 11 from Delhi to Istanbul.

The airline is working closely with the relevant authorities and taking all necessary precautions as per the guidelines.

"Flight 6E 184, operating from Jodhpur to Delhi received a security-related alert. The aircraft has landed in Delhi and customers have disembarked the aircraft, we are coordinating with the security agencies as per procedure," the airline said in another statement.

Vistara said that shortly before landing, flight UK 624 en route to Mumbai from Udaipur had a security concern and upon landing at the Mumbai airport, the plane was taken to the isolation bay for mandatory checks.

The sources said more than 20 flights have received bomb threats since Saturday morning.

On Friday, three international flights of Vistara received bomb threats which turned out to be hoaxes and one of the flights was diverted to Frankfurt as a precautionary measure.

In the past few days, more than 40 flights operated by the Indian carriers have received bomb threats which later turned out to be hoaxes.

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