France has raised its security alert to the highest level after the Moscow concert hall attack that has claimed at least 143 lives.

Friday’s massacre, claimed by Islamic State jihadists, was the deadliest attack in Russia in two decades.

In a memo sent to préfectures on Thursday and seen by AFP, Interior Minister Gérald Darmanin said that the “very high” level of the terrorist threat and persisting international tensions including the Gaza war and the Moscow attack mean that “extreme vigilance must be maintained” during the Easter celebrations.

Darmanin asked préfets to deploy law enforcement forces in front of “all” Catholic and Protestant churches, in particular during services on Friday and this weekend.

The interior minister said “particular attention” should be paid to vehicles parked near places of assembly or worship.

Two planned attacks have been foiled in France since the start of the year.

One involved a plan to stage “violent action against a Catholic religious building” by a man “clearly committed to jihadist ideology”, according to the national anti-terrorist prosecutor’s office.

The 62-year-old man was arrested and remanded in custody in early March, prosecutors said.

Catholics and Protestants commemorate the resurrection of Jesus on Easter Sunday, while Orthodox Christians will conduct commemorations on May 5th.