Flight AXB684 took off from Madurai at about 1.54pm and was due to land in Singapore at about 8.50pm, according to flight tracking website Flightradar24.
Air India Express is a wholly-owned subsidiary of Air India and a part of the Tata group.
AXB684 was one of several flights taking off from India that were disrupted on Tuesday due to bomb threats, India media outlets reported.
An Air India Express flight from Ayodhya to Bengaluru also received a hoax bomb threat, according to NDTV.
An Air India flight from New Delhi to Chicago was forced to make an emergency landing at Iqaluit Airport in Canada after a “security threat” was posted online, the airline said.
The aircraft and passengers were “re-screened as per the laid down security protocol”, the company said.
“Air India notes that it, and other local airlines, have been subject to a number of threats in recent days,” it added.
Similar hoaxes were received by India’s low-cost operator IndiGo for two flights that were due to take off – to Jeddah in Saudi Arabia and to Muscat in Oman, according to media outlets in India.
NDTV reported that a SpiceJet flight SG116 from Darbhanga to Mumbai and an Akasa Air flight QP1373 from Bagdogra to Bengaluru also received bomb threats.
