PARIS (KABC) -- More violence erupted across France Thursday, as authorities continue to search for two remaining suspects in the deadly attack at the offices of satirical newspaper Charlie Hebdo.
Police believe the two suspects that remain at large are brothers, identified as 32-year-old Cherif Kouachi and 34-year-old Said Kouachi.
Both men were listed in an American terrorist database and were on the U.S. no-fly list for years, a senior U.S. intelligence official said Thursday.
Cherif Kouachi had appeared in a 2005 French TV documentary as an aspiring rap musician-turned-jihadist and was convicted of terrorism in 2008 for ties to a network that sends radical fighters to Iraq.
The cleric "told me that (holy) texts prove the benefits of suicide attacks," Cherif Kouachi was quoted as saying in the TV documentary. "It's written in the texts that it's good to die as a martyr."
His lawyer confirmed Thursday that police tracked down the identities of the brothers because one left his ID behind in a getaway car.
Police raided and searched multiple houses in connection with the two suspects, including those of family members. Authorities also looked into French media reports that the suspects were spotted at a gas station north of Paris. The attendant told police they robbed him and stole gas.
Nine people were taken into custody and about 90 witnesses were questioned so far, according to the interior minister.
Meantime, two explosions hit near mosques, raising fears the shooting at Charlie Hebdo was igniting a backlash against France's large and diverse Muslim community. No one was injured in the attacks, one in Le Mans southwest of Paris and another in Villefranche-sur-Saone, near Lyon, southeast of the capital.
A pre-dawn shooting at the southern edge of Paris left a policewoman dead and a nearby street sweeper gravely wounded. Officials say the officer had stopped to investigate a traffic accident when the firing started. The shooter remains at large.
French Interior Minister Bernard Cazeneuve said there was no link between that shooting and Wednesday's attack, in which the three masked men barged into the magazine's headquarters with AK-47s, killing 12 people and injuring 11 others.
Eight journalists, two police officers, a maintenance worker and a visitor were killed, said prosecutor Francois Molins.
Cazeneuve said the suspects left the Charlie Hebdo office in a stolen Citroen C3 and exchanged fire with police, killing one policeman. They abandoned the Citroen and then hijacked another car, which they used to escape.
The youngest suspect, 18-year-old Hamid Mourad, turned himself in to authorities Wednesday after learning he was wanted for questioning.
Charlie Hebdo attack: Mourners show support for freedom of expression
French President Francois Holland said the country has been struck in the heart and declared Thursday to be a national day of mourning for the victims.
Charlie Hebdo had been repeatedly threatened in the past for its caricatures of the Prophet Muhammad and other sketches. City leaders in Paris are promising the attack will not stop the freedom of speech in France.
"We will keep on fighting, with this newspaper, as a free city, helping the free-thinking people and journalists," said Patrick Klugman, deputy mayor of Paris.
The surviving members of the Charlie Hebdo magazine are promising they will continue to publish the magazine on time with 1 million copies -- a 3,000 percent increase.
Meantime, U.S. Attorney General Eric Holder will be traveling to Paris this weekend for a show of solidarity and to attend an International Ministerial. Officials say meetings will include "discussions on addressing terrorist threats, foreign fighters and countering violent extremism."
ABC News and the Associated Press contributed to this report.