A priest was killed in a hostage situation at a Catholic church in Normandy, France on Tuesday. The terrorist attack, which seriously wounded at least one other person, was done in the name of ISIS, according to French President Francois Hollande.

The two men cut 84-year-old Rev. Jacques Hamel’s throat after shouting “Daesh,” another name for ISIS. The Telegraph reported that five people were taken hostage during morning Mass in the town of Saint-Etienne-du-Rouvray. Two churchgoers and two nuns were taken hostage and one is seriously wounded.

Police shot the two men as they left the building, according to The Wall Street Journal. The Islamic State said the attack was made by two of its “soldiers.” Daily Express reported that one of the attackers was a convicted terrorist known to French authorities. The man was required to wear an electronic bracelet.

Hollande called the attack a “cowardly assassination,” CNN reported. “Daesh has declared war on us,” Hollande said. “We have to win that war.”

Hollande emphasized the importance of France standing together in the face of the attacks.

“All people feel affected so we must have cohesion…no one can divide us,” Hollande said. “Terrorists will not give up on anything until we stop them.”

The Vatican released a statement on the attack, saying the Pope “shares the pain and horror of this absurd violence.” The statement said the terror was especially deplorable as it had occurred in “a sacred place where the love of God is announced.”

France has been in a state of emergency since November 2015 and the terrorist attacks in Paris. Since then, the French government has increased security services. Police have been given the authority to conduct raids and detain suspects in their homes, The Wall Street Journal reported.

The state of emergency has been prolonged after the Bastille Day attack in Nice. The French government decided to keep the number of homeland security mission soldiers at 10,000.