French police quiz father and brother of a man who took part in Paris attacks
French police are continuing to question the father and brother of a man who took part in Friday's attacks in Paris in which 129 people died.
A judicial source confirmed police were holding six people close to one of the attackers, seven of whom died in the assault, which has been claimed by the so-called Islamic State.
Police have identified one of the men as a Frenchman, on whom authorities had a dossier that marked him as a potential Islamist militant.
He has been named in reports as Omar Ismail Mostefai and described by French media as a 29-year-old petty criminal.
French media also reported that searches were also being conducted in the relatives' homes in the northeastern Aube region and in Essonne, south of Paris.
As a cross-border investigation gathered pace, prosecutors said the attacks appeared to involve a multinational team with links to the Middle East, Belgium and possibly Germany as well as home-grown French roots.
The attacks were the worst in Europe since the Madrid train bombings of 2004, in which 191 people died, and were described as an "act of war" by President Francois Hollande.
In coordination with the Federal Bureau of Investigation and other agencies, US Justice Department attorneys are working with French authorities to obtain further information that maybe relevant to the Paris attacks, a Justice Department official said on Saturday.
The worst carnage occurred as three gunmen systematically killed at least 89 people at a rock concert by a US rock band at the Bataclan theatre before detonating explosive belts as anti-terrorist commandos launched an assault, officials said.
Some 40 more people were killed in five other attacks in the Paris region, including a double suicide bombing outside the Stade de France stadium, where Mr Hollande and the German foreign minister were watching a soccer international.
Scores of people were injured, including one Irish man who underwent surgery after he was shot during the attack at the Bataclan. He is said to be in serious but stable condition.
Officials said 99 people were still in critical condition.
Mr Hollande said the attacks had been organised from abroad by Islamic State, with internal help.
Three people were arrested in Belgium as part of an anti-terrorism probe centred on a Belgian hired car found near the site of one of the Paris attacks, Belgian prosecutors said.
Meanwhile, France is observing three days of national mourning for the victims of Friday’s attacks, which included explosions outside the Stade de France where an international soccer friendly between France and Germany was being held.
Hollande also pulled out of the G20 summit being held in Turkey after declaring the first nationwide state of emergency since 1961.
France will be represented by its foreign and finance ministers.
"Faced with war, the country must take appropriate action," the president said in a solemn address after meeting security chiefs.
"France will be merciless towards these barbarians from Daesh," Mr Hollande said, using an Arab acronym for Islamic State.
Flags flew at half-mast and cinemas, theatres and other places of entertainment were closed, although schools and universities will reopen as normal on Monday.