A small group of protesters has linked arms and is chanting "Stop Kinder Morgan" as Mounties move in to end the months-long demonstration against the pipeline expansion.
Media are reporting that some people have been arrested as police begin to enforce a court injunction granted on Friday by BC Supreme Court.
A number of RCMP cruisers arrived just after 8 a.m.
Reports say some activists were taken into custody, while other protesters are observing from the sidelines.
Simon Fraser University Prof. Lynne Quarmby, a defendant in the injunction ruling, says she is very disappointed police are taking action and believes the officers are operating under "tremendous pressure" from the energy giant.
A court deadline passed Monday for protesters to vacate encampments set up to block workers from carrying out survey work for the Trans Mountain pipeline expansion.