BRUSSELS (AFP) — Belgium investigators on Monday probed a possible terrorist link in a fatal weekend shooting by a lone gunman at the Jewish Museum in Brussels that has shocked the world.

The inquiry over the shooting, which killed three people outright and fourth man who died later in hospital, was initially opened for murder and attempted “murder with premeditation.”

On Monday the inquiry was transferred to the federal public prosecutor’s office authorized to handle terrorist cases and spokeswoman Wenke Roggen said a probe had been opened into “terrorist” assassination.

Police analysis of images from the surveillance cameras at the museum show “a man killing in cold blood … with great determination,” Roggen said.

“These facts combined with the fact that the shooting lasted less than a minute and a half leads us to think there may be a terrorist motive,” she told a news conference.

This videograb released on May 25, 2014, by the Belgian federal police on demand of Brussels' king prosecutor, shows the suspect of the killings in the Jewish Museum on May 24,2014 in Brussels. (photo credit: AFP PHOTO/BELGA/BELGIAN FEDERAL POLICE/HANDOUT)

This videograb released on May 25, 2014, by the Belgian federal police on demand of Brussels’ king prosecutor, shows the suspect of the killings in the Jewish Museum on May 24,2014 in Brussels. (photo credit: AFP PHOTO/BELGA/BELGIAN FEDERAL POLICE/HANDOUT)

Earlier, deputy public prosecutor Ine Van Wymersch said the decision to transfer the case was based on “the identity and nationality of the victims”.

The victims included an Israeli couple in their 50s said to be working for the government, Miriam and Emmanuel Riva.

He was said by Belgian and Israeli news reports to have once worked for Nativ, a government agency that played a covert role in fostering Jewish immigration from the former Soviet Union.

Along with Israel’s foreign intelligence agency, Mossad, and its domestic security equivalent, Shin Bet, the Nativ agency was under the authority of the prime minister’s office.

All four victims of the shooting, which included a French woman who did volunteer work at the museum and the 24-year-old Belgian museum employee, were hit by bullets to the face and neck.

The young Belgian was said by Jewish leaders to have died Sunday of injuries in the Saturday afternoon shooting but Van Wymersch said he was still alive but “clinically dead.”

Three chilling security camera videos show the gunman, wearing a cap and sunglasses, but with his features hard to make out, walk into the museum entrance, remove a Kalashnikov-style automatic rifle from a bag and then shoot through a door before making an exit.

Van Wymersch refused to confirm or deny reports that a camera was strapped to one of the two bags he was carrying, enabling him to film the attack in the same way as did Mohammed Merah, the Frenchman who shot dead several Jews in Toulouse two years ago.

The Derniere Heure tabloid on Monday quoted a source close to the inquiry as saying: “We fear a new Merah.”

“The priority of priorities is to find this man. He must be arrested and stopped,” said Belgian Home Affairs Minister Joelle Milquet.

“We must reassure members of the Jewish community,” she added, after ordering 24/7 police protection at all of the country’s synagogues, schools and cultural centers.

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

Pope Francis said in Israel on Sunday that he was deeply saddened by the attack. “My thoughts go out to those who lost their lives in the attack in Brussels.”

Act of ‘barbarity’

The attack in the busy heart of Brussels, minutes away from a packed street-side jazz festival, came as the country headed into a crucial general election held alongside a vote for the European Parliament.

“An election day is usually a celebration of democracy. Today it is clouded,” said Belgium’s Prime Minister Elio Di Rupo. “It is on everyone’s mind.”

“In Belgium we are not accustomed to such acts of barbarity.”

In Paris, where authorities said two Jews were assaulted late Saturday outside a synagogue in a Paris suburb, the government also ordered tighter security for Jewish institutions across France.

Some 40,000 Jews live in Belgium, roughly half in Brussels and the remainder in the port city of Antwerp.

Flowers and candles were laid in front of the museum as mourners trickled by to pay respect.

“It would be terribly dangerous to see a new surge of anti-Semitism, be it from the far right or from Muslim extremists,” said 66-year-old Colette Gradom who trembled with emotion as she placed flowers at the scene.

“We feel that these actions are the outcome of a long period of hate speech against the Jews,” said Rabbi Avi Tawil, who heads the European Jewish Community Center.

There was no security at the museum leading up to the attack and Jewish community leaders said there had been no threats.

The Jewish Museum of Belgium is in the heart of the Sablon district which is home to top antique dealers. The area is a popular weekend haunt for shoppers and tourists.

In 1982, a gunman opened fire at the entrance of the synagogue in Brussels, wounding four people, two seriously.