Police detained three people on suspicion of negligence after a massive fire ripped through a Ra'anana warehouse in the city's industrial area on Sunday. Police said the fire likely erupted at a storage area for paint, before spreading and reaching gas canisters, which subsequently exploded one after the other.Heavy black smoke hung in the air and locals ran for cover during the incident. Some fell to the ground in their hurry to evacuate the area. Paramedics treated seven people for smoke inhalation, including two policemen who were responding to the incident. None were seriously hurt. Police sealed off the area to traffic and pedestrians. Within a few hours, firefighters doused the flames and brought the fire under control. Those detained were employees of the warehouse, a police spokesman said. "We still don't know what kind of warehouse this was," the spokesman added. The entire area has been enveloped by heavy smoke. Police have blocked off the area.Firefighters gained control of the blaze. Two adjacent buildings damaged, at risk of collapse.