NEW DELHI, Oct. 5 (Xinhua) -- At least two people were killed and several others injured Wednesday after an under-construction building collapsed in southern Indian city of Bengaluru, officials said.

At least four people are reported to be trapped inside.

The seven-storied building collapsed at Bellandur area of Bengaluru, the capital of Karnataka state.

"Two bodies have been retrieved from the debris and efforts are on to rescue another four persons who are said to be trapped at the accident site," P Harikrishnan, Bengaluru Additional Police Commissioner told reporters.

Locals said several people were rescued from the building, out of whom the injured were immediately rushed to hospital.

Officials said that of the two killed, one was identified as a security guard of the building.

Mayor G Padmavathi has attributed the building collapse to usage of poor quality materials in its construction.

"The building collapsed due to substandard materials used in the construction," Padmavathi said.

Police officials have registered a complaint of negligence against the building owner.