The 125,000 slum-dwellers living under a lockdown so strict that drones monitor their moves and alert police if they attempt to leave home are at the heart of India’s push to contain coronavirus.

But with only a handful of people tested so far in the country’s biggest slum, fears are growing that “Mission Dharavi” — a term coined by officials working there — may not prevent the virus from raging across the densely packed neighborhood.

Dharavi is home to an estimated one million people, who eke out a living as factory workers or maids and chauffeurs to the financial capital Mumbai’s well-heeled residents. Around an eighth of them live in hotspots where severe containment measures are being enforced.

Its narrow alleys, crowded housing and poor sanitation offer the perfect breeding ground for the virus.

“The biggest challenge is Dharavi itself… 10 to 15 people stay in one room. How is it possible to enforce social distancing?” asked city official Kiran Dighavkar.

He is overseeing an effort involving some 2,500 people, including medical workers, cleaners and volunteers, who are fighting to keep cases — at nearly 200, with 12 deaths — from spiraling out of control and overwhelming hospitals.