OTTAWA — It's too soon to start political fights over how the Montreal college shootings might have been prevented, Prime Minister Stephen Harper said Thursday.

He said all the facts aren't in yet and it's too early to begin questioning how tougher laws might have averted the rampage.

He did say, though, that current gun laws didn't work.

"The laws we have didn't prevent this tragedy, which is why our government will be in the future -- because of this incident and many others -- looking to make our laws more effective,'' he said in a brief, televised statement.

He added that it's hard to come to grips with the case of an individual who is prepared to end his life while killing strangers:

"It's impossible to explain and comprehend and I have no explanation for it. And, in a sense, let's hope none of us ever get to the stage where we can understand it.''

The prime minister called the shootings "a shocking and appalling'' tragedy.

He offered condolences to the family of the young woman killed in the rampage and said his thoughts are with the victims still in hospital.

He said he spoke to Quebec Premier Jean Charest and Montreal Mayor Gerald Tremblay on Wednesday night and offered any help they might need.

He referred obliquely to reports that the killer played a violent computer game and posted angry messages of a dark web site.

"We as a society have trouble squaring our outrage at some of the images we see, some of the messages that are communicated to people -- young people, in particular -- with our belief in freedom and our desire to avoid censorship,'' he said.

"However bad these things may be, they do not absolve any of us from our moral responsibility as individuals to act in ways that treat our fellow human beings with decency.

"Whether there's something we can do to control it, I can't tell you that, but I can tell you that nothing excuses what the killer did yesterday.''

NDP Leader Jack Layton issued his own statement expressing sorrow and offering condolences to family and friends of the victims.

He agreed that it's too early to kick off a debate on gun control, but said it will come soon.

"This is a day for remembrance and recovery, but we must also commit to take action,'' he said.

"Canadians need to feel safe at school, at work, in their communities. Yesterday's shooting is another tragic reminder of why the federal government needs a more effective strategy to control the trade in illegal firearms.''