SILVER SPRING, Md. — Dozens of people, including three firefighters, were injured after a large fire at an apartment complex in a Maryland suburb of Washington and searchers are looking for up to seven people who were still unaccounted, authorities said Thursday.

Firefighters were called to the four-story apartment complex just before midnight Wednesday and found people on upper floors who needed help, Montgomery County Fire Chief Scott Goldstein said at a briefing.

“People were dropping children and jumping out of other windows,” Goldstein said. “Everybody was getting out of the building as rapidly as possible.”

About 30 people and three firefighters were injured, with the injuries ranging from minor to serious, Goldstein said.

Goldstein said natural gas furnaces and stoves are in each of the units. It took at least an hour and 45 minutes to put out the blaze and Washington Gas helped safely turn off gas, he said. About 90 people were displaced and a shelter was opened at a community center nearby. Residents of nearby buildings that were not affected by the fire were allowed to return to their homes after several hours.

Some occupants and bystanders reported an explosion, spokesman Capt. Oscar Garcia.

Hours after the fire, smoke still was rising from the four-level garden style apartment building. Firefighters were sifting through collapsed debris and a ladder truck remained extended to the building’s upper levels.

Keni Flores said she was in an adjacent building when she heard an explosion and saw the flames.

“I just see fire everywhere,” she said. “I was thinking nobody can survive in that fire.”

Karina Hauffen was also in a nearby building at the time.