Scores of employees were evacuated from the GST Bhavan in south Mumbai after a massive fire broke out in the multi-storey building on Monday, but no casualty was reported, civic officials said.

Nearly 3,500 staffers were working in the building in the Mazagon area when the fire broke out around 12.30pm, Maharashtra deputy chief minister Ajit Pawar said.

He assured a probe into the the fire, but clarified no records were lost in the blaze due to digitisation of documents.

Firefighters battled for almost three hours to douse the flames, which started on the ninth floor of the 10-storey government-owned building, the officials said.

Speaking to media persons at the spot, Pawar said the fire spread rapidly due to presence of papers and wooden material in the building, from where thick smoke billowed out.

Over 20 fire engines were pressed into service to put out the inferno and cooling operation was underway, they said.

The fire started from the ninth floor of the building and spread to the 10th floor, the officials said.

'The fire engulfed the entire ninth floor of GST Bhavan building, said Mumbais chief fire officer Prabhat Rahangdale.

He said the building was smoke-logged and hence firemen used breathing apparatus sets to put out the flames.

According to the Fire Brigade, a portion of the building was under repair.

The Brihanmumbai Municipal Corporation (BMC) officials said scores of employees were evacuated from the fire-hit building, but no casualty was reported.

Though some staffers blamed short circuit for the fire, the officials said the exact cause was under investigation.

The building was earlier known as the Sales Tax Bhavan, but since the implementation of the Goods and Services Tax regime in 2017, it was rechristened as GST Bhavan.

Last week, a massive fire had partially gutted a three -storey commercial building in suburban Andheri.