Four Greenpeace protesters face charges after occupying the downtown Vancouver office of an energy company that plans to build an oil pipeline between Alberta and B.C., police say.

The activists entered the Enbridge office on Burrard Street and chained themselves down yesterday morning (July 28).

At around 1 a.m. this morning, police say they asked the protesters to leave peacefully, following a request from the owner of the property.

Police say one of the protesters "complied" but the chains had to be removed from the others.

The three adult females and one adult male, all from Vancouver, were arrested and later released.

The protesters face charges of mischief and assault by trespass.

Police say the demonstration was “non-violent”.

The names of the protesters have not been released.

Greenpeace is calling for a halt to the Calgary-based company’s proposed Northern Gateway project, citing concerns about the potential environmental impact.

Enbridge plans to build a twin, 1,172-kilometre-long pipeline that stretches from north of Edmonton to Kitimat on the northern coast of B.C.

But the proposal must first undergo a federal review.

Enbridge spokesperson Alan Roth told the Straight yesterday the company believes the pipeline project can be “built and operated in an environmentally responsible manner”.

Please note: This story was corrected on July 29 to indicate all four Greenpeace protesters face charges of assault by trespass.