The blackout was imposed at the Bhabha Atomic Research Centre (BARC) complex in Anushakti Nagar as part of Operation Abhyas on Wednesday night.

After a siren was sounded, one building in the complex was evacuated. Civil defence, Central Industrial Security Force, Mumbai Police and BARC security personnel participated in the exercise. Deputy Police Commissioner Navnath Dhawale confirmed that the drill began at 8 pm.