PALISADE, Minn. (AP/WCCO) — More than 4,000 workers are expected in northern Minnesota over the next couple weeks to build the contentious Line 3 oil pipeline replacement.

Opponents of the pipeline, many calling themselves water protectors, have escalated their efforts to block construction, while local law enforcement is focused on keeping the peace.

Construction has ramped up quickly on Line 3 since Enbridge Energy received its final state and federal permits late last month.

So too have the protests of activists determined to stop work on the pipeline, at least until legal challenges can be heard in court.

Opponents say the pipeline threatens spillage and irreparable damage to waters the tribes use to fish and harvest wild rice, and that the influx of construction workers into communities along the Line 3 corridor would worsen the spread of COVID-19.

(© Copyright 2020 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)