LAGOS - The death toll from the collapse of a three-story building which housed a primary school in Lagos, Nigeria's economic hub, has risen to 18, as more bodies were recovered in the early hours of Thursday.

Commissioner for health in Lagos, Jide Idris, told reporters that 18 people had been confirmed dead and more than 60 rescued.

Although rescue operation has ended, Idris said medical workers were still working to stabilize some of the victims.

According to the official, it was difficult to give an official figure of casualties now as the list of dead and injured victims was still being compiled.

At least three general hospitals and a children hospital in Lagos are currently treating victims of the collapsed building.

Medical workers earlier confirmed to Xinhua that 12 pupils, a pregnant woman, and the proprietress of the school were killed following the collapse.

Adesina Tiamiyu, head of the state emergency management agency, said rescue operation was brought to a halt at 3 a.m. local time on Thursday.

However, local residents have insisted that the operation must continue as they suspected that more victims were still trapped underneath the rubble.

Security operatives have cordoned off the area, preventing residents and people still searching for their loved ones to go near the rubble.

The collapsed building housed a school which had up to 172 registered pupils.

Soldiers, police personnel, and personnel from local disaster management agencies and the Red Cross jointly attempted to pull out victims stuck in rubles of twisted wreckage.

Heavy machinery types of equipment were deployed to the scene. The cause of the collapse is yet to be determined.

Residents have called on the state government to take firm action to reduce the incidents of building collapse in the area.

Governor of Lagos State Akinwunmi Ambode said a thorough investigation will be launched into the incident.

The collapsed building had been marked for demolition about three times, but the building regulatory agency did not demolish it.

Building collapses often occur in Lagos as some property owners and developers do not adhere strictly to planning and building laws and regulations. In most cases, heavy loads are placed on the building and substandard materials are often used in the construction work.

Kunle Awobodu, the National President of Building Collapse Prevention Guild, said there are over 1,000 buildings unfit for human habitation in Lagos Island.

"There are over 1,000 other distressed buildings of this nature in Lagos, which, if nothing is done to demolish them, they will still collapse, resulting in more calamities in the state," Awobodu said in a statement.

In his reaction, Nigerian President Muhammadu Buhari expressed sadness over the collapse and sympathized with the parents and relatives of the deceased. He also wished the injured speedy and complete recovery.