The fire was extinguished after three hours of intense effort, with the cause still under investigation, officials said.

Firefighters at the scene of a fire that killed 22 people at a seven-storey building in central Jakarta on Tuesday.Synatria Respati / AFP via Getty Images

A fire ripped through an office building in Indonesia`s capital, Jakarta, on Tuesday, killing at least 22 people, including a pregnant woman, police said.

Flames engulfed the seven-story building, sending thick black smoke billowing into the sky and causing panic among nearby residents and workers in a neighborhood in central Jakarta.

The blaze, which broke out around midday, is believed to have started on the first floor of the building in the Kemayoran neighborhood before spreading to other floors, Central Jakarta police chief Susatyo Purnomo Condro said.

Hundreds of personnel and 29 fire trucks were deployed to try to contain the blaze. The cause of the fire is still under investigation.

Firefighters move out the body of a victim from a seven-storey building in central Jakarta on Tuesday, following a deadly fire.Synatria Respati / AFP via Getty Images

Many workers in the building, which was used as a sales and storage office for a drone company, were out for lunch when a battery started sparking in a storage and testing area, said Condro, citing several witnesses.

The fire was extinguished after three hours of intense effort. At least 22 bodies - seven men and 15 women, including a pregnant woman - were recovered from the building and taken to the police hospital in East Jakarta for identification.

A resident, Intan Puspita, whose home is close to the building, told The Associated Press that the fire started with a loud bang and workers running outside. "When asked, they said that there was an alleged short circuit in one of the batteries during the charging process," Puspita said.

The fire spread quickly and she saw workers on the upper floors trying to escape by moving to the rooftop.

"I saw about 20 victims in the body bags were being evacuated from inside," Puspita said. "It was tragic."

Television reports showed the tense evacuation of more than a dozen trapped workers, including many women, from the sixth floor using an emergency ladder extended by firefighters. Each person had to be lowered one-by-one from the building, and several struggled to breathe because of the thick smoke while waiting for their turn.

Authorities said most of the victims died from smoke inhalation. Firefighters managed to rescue at least 19 trapped workers, some of whom suffered minor injuries, but were in a weak and traumatized condition. A police officer and a firefighter also experienced breathing difficulties.

"We will comb through the entire building again," Condro said when asked about the possible rise in the death toll. "Firefighters are cooling down the scene because the smoke is still thick and it is not yet possible for us to enter the structure."

Jakarta Gov. Pramono Anung called on company leaders to foster workplace safety culture and to have emergency action plans for evacuation.

"This case obviously shows the company does not provide ‘emergency access` from fire in the direct physical sense," Anung told reporters when visiting the site.

Families anxiously awaited news at hospitals or near the building occupied by PT Terra Drone Indonesia, a company that provides unmanned aerial vehicle technology for various industrial sectors such as construction, mining, oil and gas, energy, plantations and urban planning.