Ottawa police said a mother, her four children, and a family acquaintance died in a "mass killing" at a home in the Barhaven suburb of Ottawa.

Six people were found dead inside a two-story detached house on Peregan Drive late Wednesday night. One suspect was arrested at the scene.

Ottawa Police Chief Eric Stabb told reporters Wednesday afternoon: "At about 10:52 p.m. last night, Ottawa Police Service received two 911 calls from the Peregan Drive area reporting a suspicious incident where a man was screaming and asking people to call 911."

"Officers entered the house to check on the safety of those inside, and there they began to discover the six victims, the youngest of whom was less than three months old. The family is new to Canada and originally from Sri Lanka."

The victims were identified as Darshani Panbaranayaki Gama and Lewi Darshani Delanthika Ekanayaki, 35 years old, and her four children: Inoka Wikramasinghe, 7 years old; Ashwini Wikramasinghe, 4 years old; Renyana Wikramasinghe, two months old; and the elderly Kelly Wikramasinghe. A sixth man, Amarakon Mopiniesly J Jimani, 40 years old, a family acquaintance who lived in the house, was also found dead.

The woman's husband remains in hospital with serious injuries.

Stabb said: "The investigation determined that a sharp weapon was used to cause the deaths and injuries." "To be clear, this was a mass killing, not a mass shooting."

Vibrio de Souza, 19, faces six counts of first-degree murder and one count of attempted murder. Police say de Souza is a Sri Lankan citizen believed to be in Canada as a student.

Stabb said the suspect is a family acquaintance who was living in the house.

"We know there are many questions about why this tragedy occurred, and that is the focus of our homicide unit, who are thoroughly investigating this tragic crime," he added. "Our investigators and forensic teams are working hard to establish all the facts and ensure justice is served."

Several Ottawa police cars were parked outside a detached house on Peregan Drive on Thursday morning. Yellow police tape was seen blocking access to the back of the homes.

Shanti Ramesh, a resident, told CTV News: "This is a huge tragedy that happened on our street, especially with children involved."

Ramesh said she heard nothing last night but saw police officers and paramedics at the scene.

"There was a man sitting on the left side of the driveway, and he was screaming."

At 9 a.m., investigators began removing something from the house and loading it into a truck parked in the driveway. Officers covered the front door with a white sheet.

Resident Ahmed Saeed told the Canadian Press: "This is unbelievable for the entire neighborhood."

CTV News learned that Ottawa police notified the Sri Lankan High Commission that the six victims in the Barhaven incident are of Sri Lankan origin. The High Commission did not confirm if all victims are from one family. It has not received information about the suspect but is assisting police in notifying his closest relatives in Sri Lanka.

A vigil was held at Balmadio Park, at the corner of Balmadio Drive and Rodeo Drive, in memory of the victims, urging the public to avoid the crime scene while police conduct their investigation.

Ottawa Catholic school boards say two of the victims attended Monsignor Paul Baxter School in Barhaven. Inoka was a second-grade student, while Ashwini was in kindergarten.

School principal Vincenza Nicoletti said in a letter to parents: "Our deepest condolences and sincerest sympathies go to the families and loved ones of the victims during this extremely difficult time. We cannot imagine the pain and sorrow they are experiencing."

"As a close-knit Catholic school community, we are here to support each other. Grief counseling and crisis support services will be available to students and staff affected by this tragedy over the next few days and as long as needed. Our priority is ensuring everyone receives the care and help they need."

Nicoletti said the school did not inform students about the deaths.

Mayor Mark Sutcliffe posted a statement on social media calling the killing of six people "one of the most shocking acts of violence in our city's history."

Sutcliffe said: "I was shocked when I learned of the multiple homicides in Barhaven."

"We are proud to live in a safe community, but this news is disturbing to all Ottawa residents. Jenny and I are thinking of the victims' families and neighbors. Thank you to our emergency responders who are investigating and supporting those affected by this terrible event."

Prime Minister Doug Ford said on platform X, formerly known as Twitter: "My thoughts are with the families and friends of the six victims and the entire Ottawa community suffering from this terrible tragedy."

MP Lisa MacLeod said on social media: "My community woke up to shock, grief, and tragedy today after the deaths of 6 people, including four children."

"There are no words to express the sorrow I and my neighbors feel for the families, friends, and colleagues of the deceased."

Prime Minister Justin Trudeau also spoke about the killings during a press briefing.

Trudeau said: "Clearly, our initial reactions were all shock and horror at this horrific violence." He added: "We expect the community to come together to support the family and friends as Canadians always do, and we expect law enforcement to do its job and keep us all informed about this terrible tragedy."

Conservative Party leader and Carleton MP Pierre Poilievre said he is "heartbroken" to hear the news of the six deaths in Ottawa.

"My thoughts are with the victims' loved ones and the entire community feeling sorrow for this tragic loss."