(New throughout, adds Escondida and Sierra Gorda, emergency services)
By Fabian Cambero
SANTIAGO, June 7 (Reuters) - Mines in northern Chile have suspended key operations after heavy rains lashed the high altitude desert region of Antofagasta overnight and into Wednesday, companies told Reuters.
BHP Billiton's Escondida, the world's biggest copper mine, said it was snowing and all operations had been suspended.
State-run Codelco said mining activities at its flagship Chuquicamata deposit and at nearby Radomiro Tomic and Ministro Hales had been suspended as a preventative measure, while Antofagasta said Centinela and Zaldivar had suffered intermittent interruptions.
Polish miner KGHM's Sierra Gorda said it was considering whether to restrict some operations as a precaution.
The heavy rains in Antofagasta, forecast to continue through Wednesday, led Chile's emergency service Onemi to trigger its highest 'red alert' warning. No damage has yet been reported.
In April 2016, torrential downpours led rivers to burst their banks and caused suspension of mining activities in a clutch of mines near capital city Santiago. In 2015 rain made roads impassable in northern Chile's Atacama region, crimping output for a number of miners.
Chile is the world's biggest copper exporter. (Reporting by Fabian Cambero, Writing by Rosalba O'Brien; Editing by Chizu Nomiyama and David Gregorio)