At least 47 workers were killed and 46 others injured in a massive explosion at an Indonesian fireworks factory on Thursday, police said.

The cause of the fire is said to be an explosion in a pickup mini van loaded with raw materials for fireworks, Denny Hassan, a senior official of the disaster management agency in the city, told Xinhua news agency.

"The casualties have reached 47 now," he said.

The incident occurred at around 9 a.m. at the factory located in Tangerang area.

"The bodies were fully charred and we are currently looking for more bodies," a police officer said earlier.

"Now we are searching the scene to see whether there are any other casualties," said Doni Pratama, a rescuer from the Jakarta search and rescue office.

Pratama and several other rescuers from Jakarta have been deployed at the scene to give assistance to the local firefighters and rescuers.

The wounded have been treated at nearby hospitals in Tanggerang city and a police hospital in Jakarta.