The suspects used pickup trucks with fake livery resembling Brazil's Federal Police (Reuters)

Armed men stole $40 million of gold and other precious metals on Thursday from a Sao Paulo cargo terminal at South America's busiest airport, taking two hostages, police said.

Several of the suspects arrived at the Guarulhos airport in a black pickup truck with livery resembling Brazil's federal police, according to security footage seen by Reuters. Four men left the vehicle with their faces covered, at least one of whom had a rifle, and confronted workers at the airport, who then proceeded to fill up the pickup truck with cargo.

A police report said the thieves left with about 750 kg (1,650 lbs) of gold and other precious metals, along with two airport workers taken as hostages, and remained at large.

An airport spokeswoman said no one was hurt during the assault, but did not comment on potential hostages.

The airport is operated by GRU Airport, a consortium that includes Invepar, Airports Company South Africa, and state airport operator Infraero.