A man was arrested and an officer injured following an incident at a Kinder Morgan worksite in Burnaby, B.C. over the weekend.

Mounties said they were called to the facility on Shellmont Street Sunday evening for reports that someone had interfered with City of Burnaby property. When they arrived, they found a man who had allegedly moved a city-owned survey monument.

Mounties said several anti-pipeline demonstrators rushed in to block the Mountie from taking the man into custody for mischief, allowing him to evade capture.

As the officer chased after the suspect, he was pursued by several protesters from a camp set up on the site. One of the demonstrators allegedly pushed the officer to the ground, causing him to injure his knee.

Video posted to Facebook by a demonstrator and confirmed by RCMP shows the incident.

A protester can be heard telling the suspect to "just run," and "go in the forest."

As they chase the officer, she says, "Come on, push him!" and someone runs past the camera after the officer.

The Mountie was still able to chase after the suspect, and managed to arrest the 41-year-old man for mischief and resisting arrest. An investigation into the incident is ongoing, and charges are being considered for a number of demonstrators who intervened, police said.

In a statement, officers said they appreciated the co-operation of those at the site who are demonstrating peacefully. They said it was other protesters who called 911 to get help for the injured Mountie.

"Our police officers have been consummate professionals and facilitated the right of thousands of people to lawful, peaceful and safe protest in this area over the past number of weeks," RCMP Supt. Chuck McDonald said.

"Obstructing police officers and injuring them in the course of their duties is completely unacceptable and will not be tolerated."

Police said the officer's injury is minor, but bad enough that he'll be off the job for a couple of weeks.

The officer involved in the incident Sunday is not the first to be injured at the site.

Last week, three others were hurt while arresting demonstrators, including one who was kicked in the head while trying to get a protester to come down off a piece of construction equipment. 

Dozens have been arrested at the site in recent weeks for attempts to delay the $7.4-billion project, including federal Green Party Leader Elizabeth May and NDP MP Kennedy Stewart on Friday. 

Many of the arrests have come as a result of violating an injunction granted by the B.C. Supreme Court that they not come within five metres of the facility. Mounties from detachments across Metro Vancouver have been coming to the site to support their Burnaby colleagues.

Crews hired by the Texas-based oil company behind the controversial pipeline expansion are trying to clear a swath of trees before migratory birds arrive at the site. The birds' presence will put construction on hold until August.

The province attempted to challenge a National Energy Board ruling allowing Kinder Morgan to bypass local bylaws during construction, but the decision was dismissed by the federal Court of Appeal. B.C.'s environment minister said the NDP government is disappointed by the decision, but that the battle isn't over.

"Our government will continue to explore other legal ways to defend the interests of British Columbians against this unnecessary project," George Heyman said in a statement Monday.

With files from CTV Vancouver's Penny Daflos