Paris - Seven people have been detained in the hunt for brothers suspected of gunning down 12 people in an assault on French satirical newspaper Charlie Hebdo, a judicial source said on Thursday.
Confirming earlier comments by Prime Minister Manuel Valls, the source, who refused to be named, said men and women close to the two brothers were currently being questioned by police, without saying where they had been detained.
Valls, meanwhile, told RTL radio that the two suspects - who are still on the run - were known to intelligence services and were "no doubt" being followed before Wednesday's attack.
Also Read: Paris attack can't curb free speech - UK press
The masked, black-clad gunmen burst into the offices of the Charlie Hebdo magazine on Wednesday morning, killing some of France's most outspoken journalists and two policemen, before jumping into a car and escaping.
Police have issued arrest warrants for Cherif Kouachi, aged 32, a known jihadist convicted in 2008 for involvement in a network sending fighters to Iraq, and his 34-year-old brother Said. Both were born in Paris.