Delhi Police have registered a case pertaining to hoax calls following which two Kathmandu-bound flights were grounded on Wednesday at IGI Airport here minutes before departure. “The FIR was registered late last night,” DCP (IGIA) DK Gupta said on Thursday. Police received four calls — two at the DCP’s office and two at IGIA police station — claiming bombs had been placed in cabin baggage on the said flights. “All the four calls were made through Voice Over Internet Protocol and from preliminary investigation it has emerged that the caller was the same in each case,” said Gupta.