The French government is urging “extreme vigilance” in the face of a “very high” terrorist threat to religious demonstrations and places of worship on the solemnity of the Assumption, one of the most holy days in the Catholic calendar.

Gérald Darmanin, the French minister of the interior, warned regional officials in a Tuesday message through the messenger app Telegram that the country is in a “very high level of terrorist threat.” He specified that “services, gatherings, processions, and pilgrimages” at sites traditionally associated with Marian devotion face particular danger, according to French news outlet BFMTV.

Darmanin informed regional prefects that “extreme vigilance must be maintained, particularly with regard to demonstrations and places of a religious nature.” He advised government officials to be in constant contact with religious sites and to deploy extra security forces to “more sensitive” locations.

According to BFMTV, the French minister of the interior instructed local officials to advise Christian leaders on preventative security measures to detect suspicious individuals or vehicles in front of places of worship.

The French government is also reportedly likely to deploy its anti-terrorist Opération Sentinelle forces at key pilgrimage sites, such as the Shrine of Our Lady of Lourdes, where more than 30,000 faithful are expected to gather on the feast of the Assumption.

The solemnity of the Assumption celebrates the Blessed Virgin Mary being assumed, body and soul, into heaven. In France, one of the oldest Catholic countries in the world, the feast of the Assumption is a public holiday. It is usually marked by Masses and public processions.

Darmanin said that the high alert is partially due to France’s ongoing international exposure as host of the 2024 Olympics and the upcoming Paralympic Games and to “strong tensions on the international level, in particular in the Middle East.”

Due to continued terrorist threats, France has been under its highest threat security posture since March 24.

According to the humanitarian group Human Rights Without Frontiers International, there were nearly 1,000 acts of terror and intimidation against Christians in France in 2023. This past Easter the French government deployed 13,500 police officers and anti-terrorism forces to thousands of Catholic and Protestant places of worship across the country, according to Radio France Internationale.

In July, a series of coordinated arson attacks temporarily crippled train travel into Paris, impacting approximately 800,000 travelers right before the start of the Olympics. No one was hurt in the attacks.