A large group of protesters descended on Victoria's Inner Harbour to march in opposition to the federal government's purchase of the Trans Mountain pipeline expansion.

Environmental activists, First Nations groups and people waving Canadian flags and carrying inflatable orcas gathered downtown before a planned march to Centennial Square at roughly 6 p.m.

Victoria police warned drivers that there would be traffic disruptions along Wharf, Fort and Douglas streets and asked them to avoid the area.

Police said despite the traffic disruptions, the protest was peaceful. Around 20 officers were on hand out of precaution.

Several hundred protesters were expected to turn out to the event.

According to an event page, the protest was organized in opposition to the federal government's announcement on Tuesday that it would buy out Kinder Morgan for $4.5-billion to prop up the pipeline expansion.

"Participants have been asked to bring pots, pans, instruments and noise-makers to say loud and clear: No Pipeline Buyout," the event page read.

B.C. Premier John Horgan launched a reference case seeking to clarify whether the province can regulate the flow of diluted bitumen from Alberta, sparking an interprovincial trade war that ended with the government's purchase of the project.

He said earlier this week the purchase has no bearing on B.C.'s case, which is before the B.C. Court of Appeal.