Friday was a horrible day for the French people as a wave of terrorist attacks killed at least 129 people in Paris.

Gunmen and bombers went on a shooting rampage at several locations across Paris in the worst day of violence in France since World War II.

At the Bataclan rock concert hall in the heart of the French capital, four gunmen slaughtered at least 87 young people. 

Calling the attacks “an act of war,” French President Francois Hollande said Saturday that they were organized from abroad by Islamic State with internal help.

Islamic State later claimed responsibility for the attacks, saying it sent fighters equipped with suicide bomb belts and machine guns to various locations in Paris.

The jihadist group said in a statement that the attacks were designed to show that France would remain a top target as long as the country continued its current policies.

France is a founder member of the U.S.-led coalition waging air strikes against Islamic State in Syria and Iraq.

Hollande vowed that the government would wage a “merciless” fight against terrorism. France, he added, “will be triumph over the barbarism” of the IS militant group and “will act by all means anywhere, inside or outside the country.”

France should step up its fight against terrorism and show the terrorists that they can never win. And the world should be united in fighting terrorism as terrorist attacks are crimes against all of humanity, wherever they are perpetrated.

Following the attacks, U.S. President Barack Obama and German Chancellor Angela Merkel led a global chorus of solidarity with France. They should translate their words into action.

The grief of the French people was all the greater as the brutal incident took place less than a year since two gunmen from the Islamist terrorist group al-Qaida’s branch in Yemen killed 17 people during attacks at the offices of Charlie Hebdo, a weekly newspaper in Paris, for publishing satirical cartoons of Muhammad.

But the French people will overcome their grief, as they did following the January killings. They should remain united and show the terrorists that they will never succumb to threats of violence.

Terrorists, wherever they come from, should realize that they cannot accomplish anything with terrorism. The world will never tolerate terrorism. Violence only breeds further violence.

Meanwhile, the Seoul government needs to tighten security to prevent any possible terrorist attacks in the country following the carnage in Paris. We can by no means be sure that terrorists will not sneak into this country.

And Korean tourists are advised to refrain from visiting France, especially Paris, for the time being, as the government has issued a travel warning for France.