At least 12 people have been killed in a fire at an apartment building in the Bronx borough of New York.

New York City Mayor Bill de Blasio said four other people were critically injured. The fire is now under control, he added.

The building is located near Fordham University and the Bronx Zoo. The cause of the fire is not yet known.

There were more than 160 fire-fighters on scene, according to a tweet by the city's fire department.

According to the Associated Press, city records showed that the five-storey building had no lift.

However, fire escapes were visible on the building's exterior.