French police have begun interrogating the father and brother of one of the men who carried out the attacks in Paris on Friday evening that killed at least 129 people and left residents of Paris shocked..

Investigators arrested the pair in a raid on the home of a 29-year-old French gunman, whose remains were found near the site of the bloodiest of Friday's attacks, at the Bataclan concert hall in eastern Paris.

The assailant had been known to security services as having been radicalized and had a criminal record, Paris Prosecutor Francois Molins confirmed to reporters.

The attacker was one of two gunmen who blew themselves up as security forces stormed the venue shortly after midnight on Saturday. A third was shot by police.

In total, seven suicide attackers took part in the deadly rampage, all of whom died in the assault, prosecutors said. Molins said the attackers worked in three synchronized teams, wearing matching suicide vests and carrying the same weapons, Kalashnikov assault rifles.

Three teams of terrorists targeted six locations in the French capital on Friday night

Other deadly attacks took place at the national stadium and in crowded restaurants and bars of the French capital. The self-declared "Islamic State" (IS) militant group has claimed responsibility for the attacks, which happened 10 months after a similar assault on the offices of satirical magazine "Charlie Hebdo."

Police in Brussels have made several arrests in connection with Friday's attacks in Paris

Belgian link?

Police in Belgium also arrested several suspects in Brussels on Saturday, one of whom was in Paris at the time of the carnage, the country's Prime Minister Charles Michel said.

"A case has immediately been opened linked to suspect vehicles in Paris, to check people linked to those vehicles. There have been several arrests," Michel told RTL television.

He said the arrests, in the district of Molenbeek, were linked to the discovery of at least one vehicle with Belgian license plates which was found near the concert hall.

Traveled with refugees

News emerged Saturday that at least one of the assailants had registered as a Syrian refugee in Greece, where tens of thousands of migrants - many escaping Syria's civil war - have traveled in recent months on their way to northern Europe.

"We confirm that the [Syrian] passport holder came through the Greek island of Leros on October 3 where he was registered under EU rules," said Greece's Citizen Protection Minister Nikos Toskas.

German authorities said they were looking into a possible link between the attacks and the arrest in Bavaria last week of a man with a car-load of weapons and explosives.

Threat remains

The US has confirmed that it is assisting French authorities with their investigation.

International police agency Interpol, based in Lyon, France, has set up a "crisis response task force" to help track those responsible for the attacks.

In the UK, meanwhile, the emergency COBRA committee is due to meet on Sunday to assess the current security threat to the country.

Earlier Saturday, British officials called in explosive specialists and evacuated the North Terminal at Gatwick Airport after a French man disposed of what appeared to be a firearm. The man was arrested on suspicion of firearms offences.

Across France and elsewhere in Europe, security has been beefed up in the wake of the attacks, which left more than 350 people injured.

More than 1,500 French troops have been deployed to protect public buildings

In Rome, soldiers and paramilitary troops toting semi-automatic rifles patrolled outside the Colosseum and at St. Peter's Square on Saturday.

Denmark and other Nordic nations sent officers with semi-automatic weapons to patrol outside foreign embassies where usually no police are posted.

And Swedish officials increased security at Saturday night's European Championship soccer playoff game between Sweden and Denmark in Stockholm.

mm/cmk (AP, AFP, Reuters)