At least?49 people have been confirmed died and more than 90 were injured Monday after a high-rise apartment building caught fire in Shanghai, China Central Television reported.

The 28-story building at the intersection of Jiaozhou Road and Yuyao Road in Jing'an District was being renovated when it caught fire at about 2 p.m., according to a statement from Shanghai municipal publicity office.

The residential building housed mainly teachers, many of whom are retired.

The fire was brought under control after fire fighters set up hoses on top of a nearby building. The upper half of the building, which was beyond the reach of fire appliances, was engulfed by flames.

The statement said the cause of the fire was as yet unknown, but a witness said he saw construction materials burning before the fire climbed up the scaffolding and quickly spread.

A total of 25 fire units and 61 fire engines were dispatched to the scene.

At least three helicopters are hovering over the burning building, trying to rescue residents from the roof, but their efforts are being hampered by thick smoke.

More than 100 residents have been rescued. The injured have been sent to nearby hospitals for treatment.

A total of 156 families live in the building, said the statement.

A resident surnamed Zhang, who lives on the top floor, said she and a dozen neighbors escaped down the fire exit stairs.

"At first, I saw smoke belching out of the window and soon the room was engulfed by smoke too," said a woman worker surnamed Qian, who was installing thermal insulation on the 28th floor, and escaped down the fire exit stairs.