Thick smoke was seen billowing from the North Block of the Union Secretariat in Delhi on Monday, prompting authorities to deploy six fire tenders, an official said.
A police officer said some repair work was underway at the building, which might have led to a minor fire.
No casualty has been reported so far.
Delhi Fire Services received a call at 11.10 am reporting smoke emanating from the building, following which six fire tenders were dispatched, the official said.
MP Milind Deora said he noticed smoke rising from behind North Block while on way to parliament.
(With inputs from PTI)