VANCOUVER -- Dozens of people gathered outside an insurance company’s downtown Vancouver office on Friday afternoon to protest the Trans-Mountain pipeline project, and four demonstrators were arrested.

According to the Vancouver Police Department, protesters were occupying the building throughout the afternoon, and had blocked off the main entrance, preventing people from entering and leaving the building from that location.

VPD spokesperson Const. Tania Visintin wrote in an email that management had asked police to clear the area from the private building, and cited multiple concerns about personal safety from occupants while trying to leave and enter the building.

“A few protesters were aggressive and physically fought with police and damaged a glass sign in the building. Officers were called from across the city to assist,” Visintin said.

The four people were arrested for mischief and obstructing a police officer, according to Visintin.

Police said they tried to speak with protesters but that they were “unwilling to engage in dialogue.”

Around 5 p.m., a line of police officers blocked the entrance to the Bentall 3 tower on Burrard Street. There were also dozens of law enforcement vehicles on scene.

Protesters said they chose the location because the tower houses an office of AIG, the company that insures the controversial pipeline.

With files from CTV News Vancouver's Allison Hurst