A 22-STOREY abandoned office building occupied by hundreds of squatters became engulfed in flames and collapsed in the centre of Brazil’s largest city Sao Paulo, leaving at least one person dead and three others missing.

According to authorities, 400 people were registered as living in the building, which belonged to the government. The cause of the fire was not known.

Live TV images early on Tuesday showed a firefighter on an adjacent rooftop talking to a man clinging to a rescue rope and trying to escape from the upper part of the burning building.

Suddenly, the structure collapsed and the man disappeared into the rubble. Authorities said he is likely to have died, but were still searching for him.

Later on Tuesday, firefighters continued searching for additional victims amid concrete chunks and twisted metal pipes.

An adjacent building caught fire, but was evacuated and no one was injured. That blaze was brought under control relatively quickly, Sao Paulo Fire Brigade Lieutenant Andre Elias told Globo TV.

The abandoned former office building had 22 storeys, according to the fire department and not 26 storeys as reported by some media.

It once housed a branch of Brazil’s federal police and had been occupied by squatters for the past seven years.

The city and state governments have been working for years to forcibly remove squatters from buildings in central Sao Paulo, with plans for revitalising the area.

Around 50 buildings in the region were occupied by organised groups of squatters, who have pressured the government for years to provide housing for the city’s homeless.

“There is not even a minimal condition for people to live in there,” Sao Paulo state governor Marcio Franca said. “People live there in desperation. This was a tragedy foretold.”

The mayor of Sao Paulo, Bruno Covas, told reporters the state government had offered to provide housing for the displaced families, and Brazil’s President Michel Temer also offered federal assistance during a visit to the site.

Temer, a deeply unpopular president because of various corruption scandals and attempts to reduce Brazil’s relatively expansive welfare net, was forced to leave the scene quickly amid jeers from some of the displaced residents.