SAO PAULO (AP) — DNA tests have revealed the names of two more victims of the recent fire and building collapse in Brazil's biggest city.

The Sao Paulo Public Security Department said Saturday that forensic experts identified the remains recovered from the debris as 9-year-old twin brothers Wender and Welder, who lived in the building with their mother, Selma Almeida da Silva.

The department said in a statement that she is among four people believed to have been in the building when it collapsed who remain missing, the department said in a statement.

At least four people are now confirmed to have died.

Squatters were occupying the building that caught fire, and its collapse has focused attention on the housing shortage in Brazil's largest city.