A gang of eight -- in masks and armed with guns -- stole more than $7 million on Tuesday from an armored truck at Chile's primary airport in Santiago, the biggest heist in the country's history, the Telegraph reported.

The gunmen pulled up to the Santiago airport in three vehicles and help up security guards that were escorting the Brinks truck. The truck had been carrying cash scheduled for delivery to banks and mining operations in distant northern Chile.

"Initial investigations indicate the sum stolen is more than four billion pesos, but we still don't have the exact amount," said prosecutor Luis Pablo Cortes. At the current exchange rate, 4 billion pesos is about $7 million.

This is not the first time a Brinks truck has been targeted at Santiago's airport. In 2006, thieves took more than $1.5 million at the same airport terminal. At the time, that was Chile's biggest heist. The thieves were caught and are still doing prison time.

The Santiago Times reported that a security protocol likely made the heist easier for the gunmen. That protocol, established by Chile's Committee of Civil Aeronautics, prohibits anyone but airport police to enter the airport armed.

The assailants gained entry into the loading area at the airport, where the Brinks employees were to transfer the money from the truck to the plane. Outside an airport scenario, Brinks guards typically are armed.

After the thieves got control of the cash, they drove away in two cars heading in opposite directions, according to The Latin American Herald Tribune. One car took the highway that heads west from Santiago to the coastal city of Valparaiso and the other car hit local roads.

The gunmen threw out spikes on the road in an attempt to inhibit police pursuit and later a burnt-out car was found on a local road and is believe to be one of the ones used in the getaway.