Italy’s Interior Minister announced Monday that air space over Rome will be closed to drones throughout the Roman Catholic Holy Year celebrations beginning next month, due to a fear that the Islamic State (ISIS) could attack the Italian capital with drones during the celebrations.

Addressing the Italian parliament and quoted by Reuters, Minister Angelino Alfano said drones will be banned from air space over the centre of Rome throughout the Holy Year, or “Jubilee”, that begins on December 8 and is expected to draw millions of tourists to the Italian capital.

Following repeated threats attributed to ISIS on social media against Rome and the Vatican, security would be tightened around sites considered potential targets, particularly in and around St. Peter’s Square, Alfano said, according to Reuters.

“Particular attention has been dedicated to the risk of an attack from the air, using drones,” he said.

In 2014, ISIS threatened to target Pope Francis for assassination, though he nevertheless said his “door is always open” to talks with the Islamist extremists.

Meanwhile on Monday, Italy’s civil aviation authority, which had already announced an increase in security in the immediate aftermath of Friday’s Paris attacks, said it had ordered airport directors to tighten measures further.

It advised passengers on departing flights to arrive at airports earlier to allow for longer waiting times due to stricter search procedures,  according to Reuters.

French police believe at least one attacker is on the run.

France declared a state of emergency after the carnage, and Italian Prime Minister Matteo Renzi said heightened security measures were being adopted, including strengthening border controls.