Reports are emerging that French police have arrested family members of one of the Paris attackers.
They are said to be relatives of one of the suspects in the Paris attacks, who is described as a French national, born in the suburbs of the capital, according to French prosecutors.
According to Sky News, Paris prosecutor's office spokeswoman Agnes Thibault-Lecuivre declined to give further details of the relatives who have been detained, but confirmed searches are under way.
Paris prosecutor Francois Molins had earlier confirmed that one of the attackers who took part in the killing of 80 people at the Bataclan concert hall was an Islamist radical known to the security services, who had a criminal record, but had never spent time in jail.
Three other people, including a French national, have been arrested in connection with the atrocities. They were detained at the Belgian border. There were also police raids in the Molenbeek area of Brussels.
While President Hollande said the assaults were "an act of war" by IS, French Prime Minister Manuel Valls has vowed to "destroy" those behind the killings. "We will strike this enemy to destroy him. In France and in Europe, we'll chase the authors of this act, and also in Syria and Iraq. We will win this war," he said.
Thousands of soldiers have been deployed on the country's streets in the aftermath of the Paris attacks.
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