Colombian police seized a ton of cocaine stashed inside an excavator Thursday as it was being transported from the capital Bogota to the northern port city of Barranquilla.

The drugs were found inside the engine of the excavator, which looks like a small bulldozer, to try to escape detection by sniffer dogs and X-rays, Bogota Police Chief Luis Martinez said.

According to the official report, police had to recruit the help of firefighters to pry open the engine.

"This is the only such case known to the police," said Martinez, adding that the drugs were hidden in a deep compartment under iron plates.

Two people were arrested in the operation.