A dozen people suspected of having connections to one of the men responsible for last week's terrorist attacks were arrested overnight after police conducted searches in the suburbs.
Nine men and three women with suspected ties to attacker Amedy Coulibaly were arrested, Christophe Crepin, a French police union spokesman, said Friday.
"We want to know exactly what they were doing with Mr. Coulibaly," Crepin said.
He would not say where the arrests took place, although French television service BFMTV said they occurred south of Paris in the suburban area of Essonne and in the towns of Grigny and Fleury-Merogis.
Coulibaly, 32, grew up in a notorious housing project in Grigny called La Grande-Borne, officials said. He also served time at a prison in Fleury-Merogis, the nation's largest and a known breeding ground for extremists, where he is believed to have converted to Islam and met Cherif Kouachi
Kouachi, 32, last week stormed the offices of the satirical magazine Charlie Hebdo with his brother Said, 34, killing 12 people. Coulibaly killed a policewoman before taking hostages at a kosher supermarket, killing four.
A funeral service was held Friday in Paris for Stephane Charbonnier, 47, a cartoonist and editor of Charlie Hebdo killed in the attack.
Among the 12 arrested overnight was a man who supplied a car to Coulibaly, the French news channel Itele reported. Police investigated the man based on DNA found in the car, a Renault Megane, according to BFMTV.
In Berlin, police arrested two people Friday morning after searches related to an "Islamic movement," BFMTV reported, citing German police. Crepin said he could not confirm that information or address whether the arrests were part of a coordinated operation.
The police raids came the morning after Belgian officials claimed to have prevented a "large-scale" terrorist attack, killing two suspects after gunfire and explosions in the eastern city of Verviers, and arresting others in a sweep of several areas of the country.
U.S. Secretary of State John F. Kerry met Friday in Paris with French President
Hollande and Kerry laid a wreath outside the magazine's offices. They also placed a wreath outside the kosher supermarket targeted last week.
Hollande thanked Kerry for U.S. support in the crisis, saying, "You've been victims yourself of an exceptional terrorist attack on Sept. 11. You know what it means for a country. ... We must find together appropriate responses."
French Foreign Minister Laurent Fabius, who was accompanying Kerry, said authorities were working together to combat terrorism.
"Given the risk and reality of international terrorism, the action against it must also be international -- especially a cooperation with the technology we have and the Americans," he told BFMTV.
Paris is at its highest terrorism alert level, and police evacuated the Gare de l'Est train station Friday after a bomb threat, BFMTV reported.
Asked whether the counter-terrorist raids overnight showed France was at risk of further terrorist attacks, Fabius said, "We're verifying everything. The services are all mobilized. At the same time they are doing everything that's necessary to fight terrorism, we must continue to live. The terrorists want us to change the way we live. ... The united political response is the direction we need to go -- when there's a threat, we take everything seriously."