British police have arrested a 22-year-old man living in northern London in connection with the online threat that sparked a five-hour lockdown at Wilfrid Laurier University in Waterloo, Ont., on Friday.

Metropolitan Police detectives arrested the Tottenham Hale man on suspicion of malicious communication, according to Waterloo police. They say the man will remain in custody as police continue their investigation into the online message posted Friday.

The London police force became involved after the FBI tipped off the Ontario university about the online threat. It stood out because it used language similar to that found in a message posted before a mass shooting at a college campus in Oregon on Oct. 1, according to police in Waterloo.

The threat against the university's science building led to Waterloo Regional Police and the university putting the campus on lockdown while working to determine the threat's credibility on Friday. That measure was lifted at 11:30 a.m. ET.

"It's my understanding that information coming from the FBI was more of a heads-up in that, 'Here is a posting we are aware of, you need to be aware of this,' " Supt. Pat Dietrich of Waterloo Regional Police Service told media on Friday morning.

Dietrich said that threat was posted online to the anonymous 4chan forum. An image accompanying the post was also similar to one posted on 4chan before the recent shooting at Oregon's Umpqua Community College, where nine people were killed.

The lockdown at Wilfrid Laurier University was lifted more than five hours after a threat was made against the school over the internet. (Gary Graves/CBC)

Dietrich said the campus lockdown was put in place because "it is always better to err on the side of safety."

He said local police began working with the RCMP and the national cybercrime unit to identify the origin of the posting, which suggested students shouldn't enter the science building at Wilfrid Laurier on Friday. Investigators traced the message back to the northern London community, a report from Waterloo police said Saturday.