In just two weeks, Europe has suffered four attacks claimed by the so-called Islamic State.
On Tuesday, an 85-year-old priest was murdered as he conducted Mass at a catholic church in France by two knife-wielding attackers linked to ISIS.
Police shot and killed both attackers as they came out of the church building.
One of the assailants, 19-year-old Adel Keramiche, was a known jihadist sympathizer already under police surveillance.
President Francois Hollande, who went to the scene, described the killing as a "desecration of French democracy."
"In the face of this threat that has never been greater in France and Europe, the government is absolutely determined (to defeat) terrorism."
The French church attack comes just two weeks after the Nice attack in France that left 84 dead and scores wounded.
It also marks the fourth IS-related strike in Europe in July, following two terror attacks that struck the cities of Munich and Ansbach in Germany.
While Germany has been on high alert since the Brussels bombing attack in March , France has been hit particularly hard by a string of terror incidents over the last 18 months.
Gunmen killed 12 people in an attack on the Charlie Hebdo magazine offices in January 2015. In November, coordinated suicide bombings and mass shootings killed over 130 people in Paris and France has been under a state of emergency since then.
"Most of the immigrants entering Europe are Muslims, making the possibility of their links to ISIS higher. And compared to the United States, Europe's surveillance network and security intelligence is less well developed, making it difficult to prevent terror attacks from taking place."
"I see how people are worried. The shops are not completely open, only half-open, and that is what you can see here."
As Europeans witness an increasing number of terror attacks, many worry that violence is becoming the new normal.
Kim Hyesung, Arirang News.