Police gave few details Friday except to say that in both incidents "there were threats of violence and intimidation between Hells Angels and Outlaw members."
The OPP want the public's help in finding out more information.
"There were rival gangs there and that was very concerning to us," said Det. Staff Sgt. Anthony Renton, head of the OPP biker enforcement unit.
Renton said Friday the 13th attracted more than 200,000 bike enthusiasts, most of them law-abiding. Police wouldn't say where the bikers came from. In Waterloo Region, there is long-standing Hells Angels chapter and its support club, the Stolen Souls of Cambridge.
"At this time, there is no Outlaw chapter in Waterloo Region," Renton said. But Outlaw members could live locally and be part of another club elsewhere, he said.
The Port Dover event is a street party which is historically well attended by Hells Angels, police say.
This year also saw Outlaws, lots of them.
"They have not attended for several years," Renton said.
Police wouldn't say how many gang members were in the beach town but there was a "significant" presence. Renton said the bike event at Dover is a boon for people selling biker swag. Many in the crowd buy T-shirts and other souvenirs highlighting the day but police remind buyers to think twice about purchasing biker clothing and supporting criminals.
"There is a clear difference between what they (motorcycle enthusiasts) are selling and what the outlaw motorcycle clubs are selling," he said.
Hells Angels biker clothing will say "Support 81" which refers to the Hells Angels, the letter H being the eighth letter of the alphabet while the A is the first letter.
"You are putting yourself at risk by a rival gang member," he said.
"Many people see the items and don't appreciate what it exactly means by purchasing it," he said. "They don't realize they are supporting a criminal organization."
"It just looks like a fun piece of clothing," he said.
Renton said there have been incidents in the past when people have been intimidated and ordered to remove the clothing.
Officers from 20 different police services who are part of the provincial OPP biker enforcement unit were on duty in Port Dover, including Waterloo Regional Police officers.
"This is a huge event and we have our hands full to make sure people are safe," Renton said.
"It comes with tense moments when you have rival gangs in the same area and you are surrounded by that many members of the public," he said.
Anyone with information bla bla bla.....
Canada - BN.