Canada's new Prime Minister Justin Trudeau said that the country will still take in 25,000 Syrian refugees before 1 January, but he is facing increasing pressure to tighten screening procedures and slow down the process to make sure that the Islamic State infiltrators aren't among them.

In the wake of the series of attacks in Paris on 13 November, a number of politicians in Europe and North America have been warning that the countries are taking a big risk by allowing in many thousands of refugees without rigorously determining whether any could be dangerous radicals.

News that at least one of the Paris assailants may have been among refugees who passed through Greece has heightened those concerns.

Trudeau, who last month won an election fought partly on security and the refugee issue, on Sunday said "Canada is pleased to be stepping up" to take in the refugees and will integrate them into the country. "We will be accepting 25,000 Syrian refugees between now and January 1st," in the written text of a speech at the G20 major powers summit in Turkey.

The debate has been particularly heated in the mainly French-speaking province of Quebec, which -- like France -- has a large North African immigrant community and is grappling with concerns about radicalisation of Muslim youth.

Last year, two Quebec-born Muslim converts staged separate attacks on Canadian soldiers, near Montreal and on Parliament Hill in Ottawa, killing two.

BANNER ON OVERPASS

An online petition asking the government to suspend the plan to bring in the refugees was launched on Saturday by a Quebec City resident worried about "jihadists infiltrating" the country, according to Le Soleil newspaper. It had garnered more than 33,000 signatures by Sunday afternoon on the www.petitions24.net website.

"If we want to help these people well, help them at home, building a camp over there and help there," wrote one person on the French-language petition. "Short and long term, it is unreasonable and dangerous to let them in here."

Quebec City's plan to accept about 200 Syrian families was controversial even before the Paris attacks. Last week, a banner reading "Refugees: No thanks" was hung over an overpass near the city before being removed.

The opposition Conservatives, defeated last month after nine years in government, urged Trudeau to make sure it guarded Canada's security as it brought in the refugees.

"Canadians are asking the question, 'Can we do this quickly in a secure way?' And I think that's an important question," interim Conservative leader Rona Ambrose said in Ottawa.

The Conservatives had pushed for a slower refugee intake, citing security concerns, before losing office.

Security screening on the refugees will be done before they arrive in Canada, but some will only be able to get screened after they arrive, Canada's Public Safety Minister Ralph Goodale said a day before the Paris attacks.

It was not immediately clear what the screening process, which includes health assessments, entails in security checks. Those will be done by Canada's spy agency, Canada Border Services Agency and Royal Canadian Mounted Police.

In the United States, which has committed to take 10,000 Syrian refugees over the next year, vetting includes face-to-face interviews, a health screening and security checks that can take as long as two years.

ESCAPING VIOLENCE

Canada plans to bring Syrian refugees from camps in Turkey, Jordan and Lebanon, the immigration minister John McCallum has said, via a combination of commercial and military aircraft and, potentially, ships.

"How will 1000 per day be screened?" Michelle Rempel, a former Conservative legislator, asked McCallum on Twitter. "What parts of the process will be dropped?"

On Sunday, Goodale said the first round of checks would be done by the United Nations' refugee agency.

"Then we have our own, and we check all of the available information against all of the available databases to make absolutely certain about who we're dealing with," he told a CTV News political show, adding: "Can it be 100 percent foolproof? Well, nothing in life is 100 percent, but we're satisfied that the process is strong and robust."

Christine Duhaime, a Vancouver-based terrorism financing expert, said the government "has to either assume the risk or slow down the process" and take in a smaller number of refugees whose identity can be confirmed by border agents.

Friday's deadly attacks in the French capital reignited a global debate over radical Islam and the risk that militants can slip in among refugees escaping violence in the Middle East for the West.

"We should slow down and think twice, thrice or however many times it takes to be safe," said Juliet Quizzagan, a home care worker in Vancouver, who was interviewed outside a train station.

Some populist leaders around Europe demanded an end to an influx of refugees and migrants from the Middle East and Africa on Saturday after the Paris attacks claimed by Islamic State militants.

Canadian public sympathy for Syrian refugees was galvanized after the body of a Syrian toddler washed up on a Turkish beach in September and it emerged that his family had been trying to emigrate to Canada.

A spokesman for Quebec's Immigration Minister Kathleen Weil said the province would maintain the goal announced in September of accepting 2,400 sponsored refugees within the next few weeks.

In Montreal, signs of solidarity with France were everywhere, including French flags affixed to balconies and posters carried at vigils.

Some of the people at the vigils said accepting more Syrian refugees was the right thing to do. Rachid Ajdahim, 18, who lives in Montreal and is of Moroccan heritage, said the Canadian government must screen refugees to ensure they do not pose a risk but still provide them with a safe haven. "If we don't bring them here, then where will they go?" he said.

Several communities across Canada, including military bases, were preparing for the Syrian refugees. The Immigration Department hosted a conference call with community organizations on Friday to lay the groundwork for their arrival.

While details are sparse, Air Canada has offered to airlift refugees, and both the military and civilian groups are preparing to feed, clothe and house them as winter hits.

Some 3,000 refugees are expected in Alberta, the heartland of Canada's energy industry. Calgary Mayor Naheed Nenshi, the first Muslim mayor of a major North American city, dismissed social media posts that linked the Paris attack with Syrian refugees.

Asked whether he wanted a majority of refugees to be housed in downtown Calgary, Nenshi tweeted: "They're trying to escape the same people who perpetuate this kind of violence. So, yes."