PRAYAGARAJ, March 24 -- Four people were killed and another 13 critically injured after a cold storage facility collapsed in Chandapur locality in Phaphamau region of Prayagraj following an alleged loud explosion on Monday afternoon, police said, adding that efforts were on to rescue the dozens feared buried under the debris.

Police said the facility's manager was detained for questioning as part of the preliminary investigation. Following the incident, ammonia gas began leaking, and the fire brigade continued efforts to contain it till the last reports came in.

Prime Minister Narendra Modi expressed grief over the loss of lives and announced an ex-gratia of Rs.2 lakh each for the families of the deceased and Rs.50,000 for the injured f...