Photo: The Canadian Press

The flag on the Peace Tower flies at half-mast on Parliament Hill in Ottawa on Wednesday.

All the answers Canadians are seeking about this week's deadly rental-van attack in Toronto may not be forthcoming, Prime Minister Justin Trudeau said Wednesday, as he once again offered his condolences to the families of the victims.

But when asked about the emerging theory that misogyny may have played a role, Labour Minister Patty Hajdu responded by saying it's time Canadians speak up about what she called a troubling trend of hate directed at women.

While questions still persist about why a man used a rental van to ram pedestrians on a busy stretch of Yonge Street sidewalk, killing 10 and injuring 14, the families of the victims might not get the answers they want to questions of motive, Trudeau said.

"Obviously, the investigation is ongoing and I'm not going to comment on various aspects of it," the prime minister said as he entered the weekly caucus meeting on Parliament Hill.

"But a lot of people have questions as to why, and there may or may not be actual answers," he warned.

Police are investigating a message allegedly posted by the 25-year-old suspect, which suggests the attacker may have been targeting women.

Alek Minassian is charged with 10 counts of first-degree murder and 13 counts of attempted murder, with a 14th attempted murder charge possible, pending further investigation.