India, May 8 -- A series of mock drills and blackout rehearsals were carried out across Chandigarh, Mohali and Panchkula on Wednesday as part of a nationwide mega civil defence exercise in wake of escalating tensions with Pakistan.

A near-complete blackout was observed from 7:30 pm to 7:40 pm after the air raid warning sirens went off. Barring a few places, residents and establishments switched off the lights. Motorists, excluding a few, parked their vehicles on roadsides and turned off their headlights.

In Sector 61, bordering Mohali, Sector 34, Sector 16, residents said the siren was not loud enough while there were reports that streetlights remained on in Chandigarh Housing Board flats in Sector 51, parts of Ramdarbar and Modern Hous...