A 19-year-old student from Sri Lanka has been charged with stabbing to death six people he lived with in Canada, including four children from a Sri Lankan family.

Ottawa police chief Eric Stubbs said an “edged weapon” or “knife-like object” was used by the suspect, who was identified as Febrio De-Zoysa.

He has been charged with six counts of first-degree murder and one count of attempted murder.

Mr Stubbs said the victims are Sri Lankan nationals who recently came to Canada. He said they include a 35-year-old mother, her seven-year-old son and daughters aged four, two, and two-and-a-half months, as well as a 40-year-old acquaintance of the family.

The police chief said when the first officers arrived at the home the family’s father was outside and screaming for someone to call 911. Police received two emergency calls at 10.52pm on Wednesday.

The father is in hospital with serious but non-life-threatening injuries.

“This was a senseless act of violence perpetrated on purely innocent people,” Mr Stubbs said.

Sri Lanka’s high commission in Ottawa said it has been in touch with relatives in the country’s capital, Colombo.

The accused was expected to make a court appearance later on Thursday.

Police were called to the home in the Barrhaven area and the suspect was arrested quickly after that, and police said there was no continuing threat to public safety.

Don Perera, a neighbour, said he met the family who lived in the home last autumn at a Halloween party at the nearby Catholic elementary school. He said the father was from Sri Lanka.

Shanti Ramesh, who lives across the street, was alerted to a commotion late on Wednesday. From her balcony, she saw a man sitting on the driveway of the home and yelling before two police officers arrived and carried him away.

On Thursday morning, five marked police cars were parked on the street and in driveways near the home, which is a middle unit of a row of brick townhouses.

“Our first reactions are all ones of shock and horror at this terrible violence,” Prime Minister Justin Trudeau said.

Ottawa Mayor Mark Sutcliffe called the news distressing for all the city’s residents.

“It’s hard to believe,” he said. “It’s devastating and heart-breaking.”

Police have identified the victims as Darshani Banbaranayake Gama Walwwe Darshani Dilanthika Ekanyake, the 35-year-old mother; Inuka Wickramasinghe, seven; Ashwini Wickramasinghe, four, Rinyana Wickramasinghe, two, and Kelly Wickramasinghe, who was a two-and-a-half months old.

The sixth victim was Amarakoonmubiayansela Ge Gamini Amarakoon, 40.