A spokesman for the police service says there wasn't one single modus operandi in the three attacks in three days — two of which targeted kosher restaurants and one a private home in a predominantly Jewish neighbourhood.
Spokesman Simon Delorme says they haven't found evidence the attacks were aimed at any one community in particular.
About 30 people were inside Chops Resto Bar shortly after midnight Sunday morning when a Molotov cocktail was thrown through the window.
No one was injured and the suspects ran away.
One night earlier a private home was hit and, on Friday, a kosher cafe down the street from Chops was also hit.
"What we can confirm is that all three modus operandis in the three events are different," Delorme said Monday.
"So it's impossible to say if there's a link between the three cases."
Chops has been struck at least once before, in October 2012.
The Jewish organization Federation CJA says it doesn't believe the rash of firebombing attacks is necessarily anti-Semitic. It says in a statement that it is in contact with police.
"It is easy to assume that these incidents may be anti-Semitic or hate inspired events, as some have already speculated publicly," the federation said in a statement.
"We are assured that there is absolutely no evidence that these incidents — while disturbing, to be sure — are in any way motivated by anti-Semitism."
The city has witnessed such an attack in the recent past, when a Jewish school was firebombed in 2006. But Montreal police say there's no evidence these attacks were fuelled by hate.
"There's no evidence that allows us to confirm that it's a crime targeting one community in particular," Delorme said.
The incidents prompted some political reaction from Ottawa over the weekend. On Monday, Liberal MP Irwin Cotler weighed in as well.
"Deeply troubled by this pattern of events in Montreal," he wrote in a tweet. "I hope that the culprits will soon be brought to justice."