Police in Ottawa say they have made three arrests in connection with a firebombing at a downtown bank branch last month.

Video footage of the fire was posted online not long after the attack, and an activist group claimed responsibility. The incident has raised fears over security at the G20 summit in Toronto later this month.

Three suspects -- a 50-year-old, a 58-year-old and a man in his late 20s -- were taken into custody. It's expected that the exact charges and the identities of the suspects will be made public on Saturday morning.

Ottawa Police Const. Jean-Paul Vincelette confirmed on Friday that charges will be laid very soon. He noted that the RCMP and the Ontario Provincial Police were also taking part in the investigation.

The incident occurred during the early morning hours of May 18. Video footage showed a small group of people running away from the burning bank.

There were no injuries, but the fire burned through the bank's lobby and left $300,000 worth of damage.

A so-called anarchist group said they were responsible for the fire. They also promised to take more action during the G20 Summit in Toronto and the G8 meeting in Huntsville, Ont., which both occur next week.

The group said the attack was carried out against RBC because the bank was a major supporter of the Olympics in Vancouver. The group said the Olympics had taken place on "stolen" native land.

RBC said the group was using "inflammatory statements" and was using violence.

Ottawa Police Chief Vern White said the attack was a case of "domestic terrorism."