India, July 8 -- Pigeons are a familiar sight across Lutyens' Delhi, perched on sandstone buildings, traffic lights, lamp posts and scattered across footpaths. But the birds have lately become an unlikely challenge for Delhi Police, whose officers said they have been interfering with one of the Capital's most critical surveillance systems by obscuring CCTV camera lenses with droppings.

To tackle the problem, Delhi Police has begun installing "anti-bird spikes" around CCTV cameras across the high-security zone. Officials said the spikes are meant to prevent pigeons from perching directly above cameras, where droppings have repeatedly blurred lenses, obstructed footage and affected surveillance.

The slim plastic spikes -- commonly seen on...