NEW DELHI: Days after the blast near Red Fort, in which nine people were killed and 30 injured, security agencies were on Wednesday thrown into a tizzy after IndiGo received a message threatening that five airports, including Delhi and Mumbai, would be blown up within 24 hours.The bomb disposal squad, along with fire department personnel, immediately launched an extensive search operation at IGI Airport that continued for several hours. The threat was later declared a hoax.This came on a day an Air India Express aircraft en route from Mumbai to Varanasi received a bomb threat.An official said IndiGo’s grievance portal received a message at 3.14pm saying, “Indian Airports will be attacked within 24 hours – Delhi, Chennai, Hyderabad, Mumbai, Trivandrum.” Security agencies, including the Bomb Threat Assessment Committee (BTAC), were soon alerted. BTAC termed the threat “non-specific”. The fire department, which received a call around 4pm, dispatched three fire tenders to the spot.“After the blast near Red Fort, security was already stepped up across airports. However, it was further strengthened after the threat. After checking, nothing was found,” said another official.