At least two people were killed while eight others were injured after a multi-storey residential building in Lyari's Liaquat Colony collapsed on Sunday night.
Edhi officials said rescue operations were under way to find those buried underneath the rubble.
Speaking to Dawn.com, Saad Edhi said that rescue workers had pulled two bodies from the rubble; one of a woman and the other of a child. He added that between eight to 10 injured citizens were taken to Civil Hospital for medical treatment.
"We were told that the building was more or less empty. Residents told us that very few people were present [when it collapsed]." He added that approximately 10 people were buried underneath the rubble, adding that rescue operations could take around 10 to 12 hours.
Earlier, the Karachi police office had identified four people that were injured, including a woman and a child, and said that rescue work was under way.
Speaking to Dawn.com, City SSP Muqaddas Haider said that residents had been given notices due to the dilapidated state of the building, because of which many families had vacated their apartments.
On Sunday morning, another major crack had appeared in the building due to which several more people had evacuated their apartments, he said. He added that it was still too early to say how many people had been killed.
Taking notice of the incident, Sindh Chief Minister Murad Ali Shah directed the Karachi commissioner to begin rescue operations, according to a statement by his spokesperson.
The chief minister directed officials concerned to carry out the necessary rescue work and to submit an inquiry report on the incident.
According to Sindh Building Control Authority (SBCA) spokesperson Ali Mehdi Kazmi, the collapsed building had been declared dangerous.
"The residential building was in a dilapidated state and was old. Notices were issued six months ago to vacate the building and around two months ago it was also recommended that the electricity and gas supply be cut."
Despite this, the district administration did not take the necessary action, he said.
In March, 27 people were killed after a building collapsed in Karachi's Gulbahar area. The residential building had fallen on two adjacent structures, bringing them to the ground as well.
Following this, a case was registered at Karachi's Rizvia Police Station in the state's name against the building owner.
The first information report included clauses 322 (causing death without intention), 119 (Qisas), 337 (causing bodily harm), 427 (mischief causing material damage) and 190 (aiding and abetting) of the Pakistan Penal Code.