Ottawa police are investigating the third hate crime to occur this week after anti-Semitic graffiti was spray-painted on the side of a Jewish Modern Orthodox synagogue in south Ottawa.

Police were notified at around 7 a.m. ET Thursday after congregates spotted it at the Machzikei Hadas synagogue on Virginia Drive in the Alta Vista neighbourhood.

Two swastikas were spray-painted on its front doors and another was spray-painted on a nearby sign.

Security cameras also were spray-painted to prevent them from recording, and a number of offensive phrases were spray-painted on the synagogue's outside walls.

Machzikei Hadas synagogue Ottawa swastika racist Nov. 17 2016

Two swastikas were spray-painted on the front doors of the synagogue. A nearby sign was also vandalized. (Andrew Foote/CBC)

'Incredibly, incredibly troubling'

The graffiti comes just days after a swastika and the word "k---e" were spraypainted on the front door of a woman who runs a Jewish prayer centre in the Glebe.

Police say they're also investigating a graffiti incident at Ottawa's Torah Institute on Coldrey Avenue.

Idan Scher, the Alta Vista synagogue's rabbi, and Dr. Reuven Bulka, its rabbi emeritus and a prominent member of the community, surveyed the damage at Machzikei Hadas on Thursday morning.

"I think that this is far more than just regular graffiti vandalism," Scher told CBC News. "When you take a look at the words and the swastikas on the doors, these are representations of the systematic annihilation of our people.

"So obviously this is incredibly, incredibly troubling and I cannot exclaim the gravity of this vandalism in any greater terms than that."

Prime Minister Justin Trudeau and Ottawa Mayor Jim Watson tweeted messages Thursday denouncing the act.

Machzikei Hadas synagogue graffiti racist Ottawa Nov 17 2016

Some of the synagogue's security cameras were also spray-painted. (Andrew Foote/CBC)

Crimes used similar symbols, words

"These are hate crimes," Ottawa police Chief Charles Bordealau said Thursday.

"These three incidents have some similarities. They're targeting the Jewish community and they have the same type of symbols and words used."

There are currently no suspects, Bordeleau said. Investigators are analyzing evidence collected from each incident and conducting interviews.

So far this year police have received reports of 64 hate crimes, down slightly from last year's total of 88.

Bordeleau said the force recognizes the significance of three cases in one week. 

"It's hurtful, it's offensive, and I can appreciate how they're feeling right now," he said. 

Synagogue vandalized in the past

It isn't the first time the synagogue has been vandalized, but it has been many years since the last incident, Bulka said.

"You never get used to it," he added.

"It's a terrible situation. We're hoping that it's just one lone crazy [person], and it's a shame that one lone crazy can really obscure some of the wonderful things that are happening in our community," Bulka said, referring to the outpouring of support shown by other religious groups after the vandalism of the Jewish prayer centre in the Glebe.

"After the incident that happened a few days ago, leaders from all sectors called to express their outrage about what happened," he said. "... So it's really upsetting, but on the other hand it's heartening that the community realizes what it is and has basically said, 'We're with you together, and an assault on you is an assault on us.'"

The Machzikei Hadas congregation started in 1907 in the ByWard Market and has been in Alta Vista since 1973.

Machzikei Hadas graffiti

A man begins to wash the graffiti on the synagogue. This latest spray-painting incident comes just days after a swastika and a derogatory word were put on the front door of a Jewish prayer centre in the Glebe. (Andrew Foote/CBC)