The collapse took place around 12.30 p.m. in con gested Sadar Bazar area of old city.
Two male bodies were recovered from the debris.
"As the rescue operation is on, some more people are expected to be trapped inside the debris," a police officer said.
The deceased, in their late 20s, looked like labourers, but their identity was yet to be ascertained.
"At least 11 people were injured in the incident. They have been admitted to the Sushruta Trauma Centre, Hindu Rao and Ram Manohar Lohia hospitals. One of the injured is said to be critical," the officer said.
According to the Delhi Fire Service, three excavator machines were rushed to the spot to remove the debris and rescue those trapped.