Anti-nuclear protest continues in SA

Anti-nuclear activists are maintaining a blockade of the Olympic Dam uranium mine in South Australia's north after confrontations with police.

The action, which included blocking the main road to the mine, continued into the night on Sunday.

It involved a bonfire as well as singing and chanting early in the day, but escalated later to a clash with a strong police presence in when protesters attempted to move a large block of fake uranium onto the road.

Police said the group had repeatedly been told not to place props on the bitumen and officers moved in quickly to seize it.

That prompted some clashes, although there were no reports of injuries and police said they made no arrests.

BHP Billiton said despite the main road being blocked all day, operations had continued as normal with a shift change completed successfully.

Sunday's action was part of a planned three-day protest at the mine site which began on Friday.