Firebombs and pig heads thrown into mosques. Veiled women subjected to crude insults in the street. The Internet awash with threats against Muslims. Europe's Muslims are feeling the heat of a fierce backlash following last week's terror attack against French satirical magazine Charlie Hebdo.

A climate of fear is taking hold in Europe, as ordinary people increasingly heed rightist rhetoric equating the millions of peaceful Muslims with the few plotting murder and mayhem.

Abdallah Zekri, head of the National Observatory Against Islamophobia, said that in a 48-hour period after the Wednesday massacre at Charlie Hebdo, 16 places of worship around France were attacked by firebombs, gunshots or pig heads — a major insult to Muslims who don't eat pork.

The three-day terror spree in Paris claimed the lives of 17 victims, and traumatized a continent already brimming with anti-immigrant sentiment. Brothers Cherif and Said Kouachi — the Al Qaeda-linked suspects in the magazine attack — were killed in a shootout at a printing plant north of Paris; their apparent accomplice Amedy Coulibaly was shot dead in a near-simultaneous raid at a Jewish market, where he had holed himself up with hostages, killing four.

French authorities are warning the nation against linking French Muslims with terrorists.

"The terrorists' religion is not Islam, which they are betraying," Foreign Minister Laurent Fabius said last week. "It's barbarity."

Concerns about a backlash against Muslims were discussed Monday during a counter-terrorism meeting at the Interior Ministry. "We said above all, pretty unanimously, that in France there are 5 or 6 million Muslims. These (terrorist) issues concern 1,000 individuals," said Socialist lawmaker Patrick Mennucci. "We should be careful not to stigmatize anyone."

Coulibaly's mother and daughters, presenting condolences to the victims, issued a plea in a statement delivered to the French press "that there will be no amalgam between these odious acts and the Muslim religion."

Yet Muslims and some experts said that it was inevitable that Muslims would fall under suspicion after the attacks, despite a unity march on Sunday — described as the largest in French history — in which throngs of Muslims participated.

The rising far-right in France and other European countries has been driven by an anti-immigration, anti-Islam message. National Front leader Marine Le Pen seized upon the Charlie Hebdo attack just hours after it happened, suggesting it was a vindication of her party's xenophobic stance. Extreme-right groups across Europe have increasingly been striking a chord with ordinary citizens voicing fears their culture is being uprooted by an alien civilization.

The fledgling German group that calls itself Patriotic Europeans Against the Islamization of the West, or PEGIDA, drew its largest crowd ever Monday night — a reported 40,000 — at its weekly rally in Dresden, after organizers declared it a tribute to the victims of the French attacks. No anti-Islamic acts have been reported in Germany since the terror.

French Muslims were already facing a backlash triggered by terror acts by French radicals twisting their religion — particularly since the rampage in southern France in 2012 in which Mohamed Merah killed three children at a Jewish school, a rabbi and three paratroopers. Anti-Islam sentiment spread further after the killing of four people by a French Muslim at the Brussels Jewish Museum in May.

Anti-Muslim and anti-Jewish incidents rose throughout 2014 in France, which has Europe's largest communities of both religions.

"For Muslims, the shock is grave in this climate of Islamophobia, of aggressions against places of worship," read a statement by Dalil Boubakeur, head of the French Council for the Muslim Faith and the most visible Muslim in France.

France's state of high alert after the Charlie Hebdo rampage — with 10,000 soldiers deployed in the streets — may deepen a sense of siege within the Muslim population.

French authorities have long warned that France is a preferred target of Islamic extremists. France routed Al Qaeda from northern Mali — two years ago to the day before Coulibaly attacked the Jewish market — and is now carrying out airstrikes in Iraq against the Islamic State group. Both Al Qaeda and ISIS have threatened France.

But the attacks have had an effect outside France, too. In the Netherlands, Muslim groups and the government met Friday and said they plan to register anti-Muslim incidents. A burning object was thrown at a mosque in Vlaardingen, on the outskirts of Rotterdam.

"Everyone has this uncomfortable feeling, a sense of being threatened — Muslims because they are afraid to be stigmatized and that they will be attacked too," said Imade Annouri, a Green parliamentarian of Belgium's regional legislature of Flanders and an expert on integration issues.

TellMAMA, a British group that tracks anti-Muslim attacks, reported 50-60 cases of specific online threats to individuals over the weekend.

"The sheer volume is unbelievable," said the organization's director, Fiyaz Mughal, who fears virtual assaults could spur real ones in the street. Mughal said that after the slaying of British soldier Lee Rigby in London, the group was able to gauge how threats made on Twitter and Facebook translated directly into attacks on individuals or mosques.

Mohamed Ali Adraoui, a fellow at the European University Institute, suggested that hatred of Islam could morph into an assault on a mosque, in France or elsewhere.

"If you can do that in Charlie Hebdo offices, you can do it in a mosque," he said.