Indian police officers recently questioned two British nationals at a hotel near the Delhi Airport on the grounds of monitoring air traffic communications between the airport’s traffic controllers and pilots.

The Britons have been guests at the Radisson Hotel over the weekend. Upon check-in, they have specifically requested a room that overlooks the airport’s runway.

The men had been found in possession of highly powered binoculars, laptop, cameras and radar-scanning equipment. The Britons, named Steve Ayres and Stephen Hampton, told the investigators that they were not spying and merely like plane spotting, a kind of hobby that is not popular in India.

Rajan Bhagat, Delhi police spokesman, said that the Britons were not detained nor arrested but just questioned for suspicious activities. Meanwhile, The British high commission based in Delhi was made aware of the incident and offered consular assistance to the Britons.

The two plane spotters were recently released without charges, said the Foreign and Commonwealth Office (FCO). The agency added that the two Britons were cleared, but the case is not yet closed.

India is currently on high security alert after a bomb blast in Pune, a city located in the central state of Maharashtra. The incident happened on a café frequently visited by tourists. The bombing left nine people dead.