Two autonomous trucks collided at BHP Group's Jimblebar iron ore mine in Western Australia's Pilbara region over the weekend, The West Australian reported March 18.

No one was injured.

This is the second accident in five months for BHP in the Pilbara. In November 2018, the company deliberately crashed an iron ore train that had taken off without its driver after an emergency brake shut down, leading to A$300 million in damages.

One of the trucks was traveling at about 27 kilometers per hour and the other at 14 kilometers per hour when they slid into each other following heavy rainfall. Operations resumed a few hours later.

Fortescue Metals Group Ltd. reported a similar incident involving driverless vehicles at its Christmas Creek iron ore mine in February. In that case, one truck reversed into another stationary truck after a Wi-Fi outage. A remote operation error allegedly caused the accident when the connection was restored.

Fortescue said it was not a failure of its autonomous haulage system.