A second man suspected to have been among the attackers in Paris on Friday is very likely to have entered Europe though Greece, Greek government sources said Saturday, as Belgian police arrested at least three people in a district of Brussels on in connection with the attacks after an anti-terror probe was launched.
Earlier, a Greek government minister said the holder of a Syrian passport found near the body of one of the gunmen who died in the attacks in Paris had passed through the Greek island of Leros in October with a group of 69 refugees and had his fingerprints taken by authorities there.
Police declined to give his name "It is very likely that a second suspect also passed through Greece. The investigation is continuing," one of the sources said.
VIDEO: French police engaged in a firefight with gunmen outside the Bataclan club in Paris:
The source said there were no official records showing the man had left Greece, but that authorities believed he may have crossed into Macedonia.
Greek police were also asked by French authorities to check on the holder of an Egyptian passport that was apparently found near the body of another attacker, the police source said.
Meanwhile, Belgian police arrested three people on Saturday in raids in a poor, immigrant quarter of Brussels as they pursued emerging links between the Paris attacks and an Islamist bastion in France's northern neighbor.
Prime Minister Charles Michel said at least one of those held from the inner Brussels neighborhood of Molenbeek was believed to have spent the previous evening in Paris, where two cars registered in Belgium were impounded close to scenes of some of the violence, including the Bataclan music hall.
"Police operations will go on," Michel told RTL television as local media reported continued security activity overnight in Molenbeek, west of the city centre, which is home to many Muslims, notably families originally from Morocco and Turkey.
A French prosecutor said a car hired in Belgium was linked to the attacks and that a Frenchman living in Brussels rented it and was later stopped early on Saturday at the Belgian border.
Earlier, a source close to the inquiry in France said one of the gunmen who died after attacking the concert hall had French nationality and was known to have ties with Islamist militants, a source close to the inquiry into a series of deadly attacks in Paris said on Saturday.
The source said that the gunman's body had been identified by his fingerprints and that he was from the Courcouronnes suburb south of Paris. He was one of four terrorists who attacked the concert hall. The gunman's father and brother, both living in the vicinity of Paris, were taken into custody and their homes were searched.
Gunmen and bombers attacked the Bataclan music hall, restaurants, and a sports stadium at locations across the French capital on Friday, killing at least 129 people and wounding 352, more than 90 of them critically. Islamic State claimed responsibility on Saturday for the coordinated assault. President Francois Hollande said the attacks amounted to an act of war against France.
The attackers likely worked in three coordinated teams, Paris Prosecutor Francois Molins said on Saturday evening.
Late night on Saturday, heavy police presence was seen at the Pullman Hotel on Avenue de Suffren near the Eiffel tower, a Reuters witness said, but shortly after the French interior minister released a statement saying the incident was a false alarm.
French authorities are having a hard time dealing with security arrangements in Paris following Friday evening's wave of terror attacks in the city. The French government has ordered the deployment of an additional 1,500 troops to reinforce security forces already on the streets of the city, but in a metropolis the size of the French capital, there is no way to secure every spot and in large portions of the city center, there were no soldiers or police in sight.
Despite Friday's attacks, cafes and restaurants have been open and are still attracting crowds. Nevertheless, the city's Saturday street markets did not open, on orders from authorities seeking to avoid gatherings by members of the public. The main concern at the moment is that, beyond the eight terrorists who were killed, there could be accomplices or other participants who did not die at the site of the six attacks on Friday, and who are hiding in the city, intending to commit additional attacks.
Despite existing orders since the beginning of the year regarding increased security around synagogues and other Jewish institutions, some Paris synagogues held prayer services on Saturday morning without security on hand. The authorities apparently assumed that services would not be held due to instructions for people not to congregate in one place, worshippers said, but since Sabbath-observant Jews had not watched television on Friday night and were not aware of the directives, they came to synagogue in any event.
World leaders responded with shock and pledges of solidarity for France following the killing of scores of people in attacks in Paris on Friday night, though there was little action any could immediately take.
U.S. President Barack Obama was slated to be briefed by his top advisers on Saturday on the latest intelligence on Friday's deadly attacks in Paris, a White House official said. "Before departing for the G20 Summit, the president will convene his National Security Council to review the latest intelligence surrounding the attacks in Paris," the official said.