PARIS (AP) — French President Emmanuel Macron said on Thursday that France is reinforcing its border controls after a series of terrorist attacks that hit the country in recent weeks.

Macron said the number of police and troops in charge of border controls will double from 2,400 now to 4,800. They will focus on fighting illegal immigration and smuggling activities, he said, during a visit to a frontier post in Le Perthus, at the border with Spain.

“We see very clearly that terrorist actions can actually be led by some people who use migratory flows to threaten our territory. So we must reinforce our controls for reasons of national security,” Macron said.

Macron notably referred to the Islamic extremist attack at Notre Dame Basilica in the city of Nice that killed three people last week. The chief suspect, Ibrahim Issaoui, is a 21-year-old Tunisian who transited through Italy in September en route to France. Issaoui is now in a French hospital after being wounded by police as they arrested him.

In addition, Macron said he will push for changes to make controls at the European Union's external borders more efficient.

“Attacks in France, in Austria a few days ago in Vienna, show us that the terrorist risk is everywhere, that (terrorist) networks are global ... which forces Europe to intensify its response,” he said. France will present its proposals at a European summit in December.

The country raised its security alert to the maximum level after Nice attack on Oct. 29.

It was the third attack since Charlie Hebdo republished the caricatures of the prophet of Islam in September as the trial opened for the 2015 attacks at the paper’s offices and a kosher supermarket. The gunmen in that attack claimed allegiance to the Islamic State group and al-Qaida, which both recently called anew for strikes against France.

Herve Cazaux, border police director in Le Perthus region, said police have arrested 11,200 people seeking to cross the French-Spanish border illegally so far this year, compared with 5,500 last year.

This is in part explained by France's spring pandemic lockdown, under which the borders were closed until June 20, and by an increase in numbers of migrants this summer, many travelling via Spain from Algeria and Morocco, Cazaux said.