Uranium activists have smashed the outside gate of BHP Billiton's Olympic Dam mine, with tensions rising following the third day of protests.
ABC News reports protestors broke the lock on a perimeter fence but were stopped proceeding further by the main reinforced steel gate.
The Olympic Dam mine sits atop the largest known uranium deposit in the world, and protestors are opposed to the use of uranium and the planned expansions on site.
BHP is planning a multi-billion dollar expansion at Olympic Dam, which will keep the mine operational for many decades.
If the company proceeds copper production is expected to triple to around 750,000 tonnes and uranium oxide production is expected to climb to 19,000 tonnes.
While the South Australian Government is supporting the development BHP has previously hinted at pushing back the massive expansions.
SA Premier Jay Weatherill has warned the company will lose Government approvals if it does not make a firm decision on the expansion before the end of the year.