European Jewish leaders on Sunday praised the arrest of a suspect in the Brussels Jewish Museum attack and called for preemptive measures to protect Europe’s Jewish communities from additional attacks.

Mehdi Nemmouche, a 29-year-old French citizen from the northern French town of Roubaix, was arrested Friday in Marseille in possession of a gun and a Kalashnikov assault rifle of the sort used in the May 24 attack that claimed the lives of four people, including two Israelis.

“We are very satisfied with the work of the French authorities in finding the perpetrator of the cold-blooded murders last week,” European Jewish Congress President Moshe Kantor said in a statement. “However, for too long authorities in Europe have acted speedily after the fact. it is now time for all to turn attention and set as the highest priority the prevention of these vicious crimes.”

Kantor called for “pan-European cooperation at the highest levels” to combat the “wave of terror against the Jews in Europe.” The EJC president also stressed that efforts to “clamp down much harder on the spread of hate and focus on gathering intelligence on potential threats, especially against those who become global Jihadists by traveling to places like Syria where they learn hate, terror and murder.”

Nemmouche is suspected of having jihadist links. He visited war-torn Syria in 2013.

Moshe Kantor the president of the European Jewish Congress. (photo credit: Orel Cohen/FLASH90)

Moshe Kantor the president of the European Jewish Congress. (photo credit: Orel Cohen/FLASH90)

A recent EU police organizations’ annual report claimed that the terror risk in EU countries was “acute and diverse,” in part due to the the number of residents who left to fight in the Syrian civil war who are “posing an increased threat to all EU member states on their return.”

“European authorities have to prevent their citizens from traveling to war zones like Syria and Afghanistan, because they are importing their battles to our continent,” Kantor said. “After the murders at the Jewish school in Toulouse during 20012 there was a lot of hand-wringing and lofty promises that this wouldn’t happen again.”

Joel Rubinfeld, former head of the Central Council for Jews in Belgium, said the arrest came as “a relief, but the issue is still worrisome.”

“It’s important that states whose citizens visit Syria will take all possible measures to ensure that a similar incident will not repeat itself,” he said.

A picture released on June 1, 2014 shows the 29-year-old suspected gunman Mehdi Nemmouche. (photo credit: AFP PHOTO)

A picture released on June 1, 2014 shows the 29-year-old suspected gunman Mehdi Nemmouche. (photo credit: AFP PHOTO)

The shooting by a lone gunman in the Brussels Jewish Museum on May 24 killed three people outright — an Israeli couple and a French woman, while the fourth victim, a 24-year-old Belgian man, was left clinically dead.

Authorities had released chilling security camera footage of the gunman wearing a cap and sunglasses, walking into the museum, removing an automatic rifle from a bag and shooting through a door before making an exit.

Belgian media reported that the assailant used a camera to film his attack in the same way as Mohammed Merah, the Frenchman who shot and killed Jewish schoolchildren in Toulouse two years ago.

Customs officials detained Nemmouche at Marseille’s coach station on board a bus arriving from Amsterdam via Brussels.

He is being questioned by the DGSI, France’s internal intelligence agency, who can hold him for up to 96 hours, until Tuesday, or 144 hours, to Thursday, if investigators invoke an imminent terrorist threat.

Sources close to the investigation told AFP that Nemmouche remained silent during the first 24 hours of interrogation.

The attack was the first such incident in more than 30 years in Belgium and has revived fears of a return of violent anti-Semitism to Europe.

The profile of Nemmouche also stands to revive a row in France over the monitoring of those who leave to country to fight in Syria.

France unveiled plans in April to try to stop the increasing numbers of young French Muslims heading to fight in Syria’s civil war and becoming radicalized before returning home.

President Francois Hollande said Sunday that the suspect was “arrested as soon as he set foot in France.”

“The government is mobilized to track down jihadists and prevent them from causing more harm,” he said, adding that the action plan to fight them will “be strengthened in the coming months.”

According to the latest figures, some 780 people have left France to fight with jihadists in Syria.