There was a sudden wave of bomb threats against more than 400 domestic and international flights of Indian airlines.

This wave took place over approximately two weeks until October 28, according to a report by Indian media outlet The Hindu.

“In 15 days, more than 410 domestic and international flights operated by Indian carriers received false bomb threats,” the report said, adding that most of the threats were issued via social media.

On October 28 alone, such threats were made against more than 60 flights.

Air India and IndiGo each received threats for 21 flights, while Vistara saw 20 flights affected. It is not known how long this disruption lasted.

IndiGo said two of its flights had to be diverted due to the threats, Business Today reported. Flight 6E 133, traveling from Pune to Jodhpur, was diverted to Ahmedabad, and 6E 87 from Kozhikode to Dammam was diverted to Mumbai.

An Air India spokesperson confirmed to The Hindu that a number of its flights were subject to security threats received on social media on October 28.

“Following established protocols, the relevant authorities were immediately alerted and all safety procedures were strictly adhered to, in accordance with the directives of the regulatory authorities,” the spokesperson said in a statement.

Amid the flood of bomb threats, India’s IT ministry advised the public to observe “due diligence obligations and promptly remove or disable access to disinformation” on social media in the strict deadlines set by IT rules.

The country’s civil aviation ministry is also taking steps to prevent such incidents from happening and to ban those who participate in or direct such threats from flying, The Hindu said in a report.