The blaze was reported at 4.14 am on the 10th floor of the Milan Hill building in Shastri Nagar locality, Thane Municipal Corporation`s disaster management cell chief Yasin Tadvi said.

The fire spread through the electric duct between the 10th and 13th floors, causing heavy smoke inside the building.

Nearly 70 residents were trapped due to the smoke and were later rescued by the fire brigade and disaster management staff, the official said.

Two residents, aged 62 and 74, suffered burn injuries and were admitted to private hospitals, Tadvi said.

The fire caused damage to the electric duct and the main doors of two flats on the 10th floor, he said, adding the blaze was extinguished by 5.30 am. The cause of the blaze was under investigation.