Apple supplier Pegatron temporarily halted the assembly of iPhones at its facility in southern India on Monday after a fire on Sunday night.
No casualties or injuries were reported in the blaze and the factory near Chennai, Tamil Nadu state, was not in operation at the time of the incident due to a holiday, three sources told Reuters.
Pegatron, which is based in Taiwan, cancelled the first two shifts on Monday and has not yet informed assembly staff whether the third shift of the day will go ahead, the sources said.
The extent of the damage caused by the fire is not yet known.
An emergency official said firefighters tackled the blaze for about five hours.
"There are no injuries, no casualties nor damage to other assets. The cause of accident is currently under investigation by [the] relevant authority," Pegatron said.
Pegatron currently accounts for 10 per cent of iPhone production in India, research firm Counterpoint has said.
The company, which started iPhone assembly in India in September last year, is also in talks to open another contract facility for Apple near its Chennai site.