Nagpur, Dec. 16 -- An unidentified drone was spotted flying over the airstrip of Nagpur-based Solar Industries, a manufacturer of defence-related equipment, triggering an investigation by security agencies, senior police officials said today.

According to the officials, the drone was observed over the company's airstrip on the Nagpur-Amravati road, about 40 km from the city, at approximately 7.15 pm on December 9. However, due to poor visibility at night, the exact size and nature of the drone could not be ascertained.

An FIR (first information report) has been registered against an unknown person at Kondhali police station and investigations are currently underway.

Police said security personnel at Solar Industries first noticed blinkin...