On the day after masked gunmen stormed the offices of the French satirical magazine Charlie Hebdo and killed 12 people, a manhunt is underway across France for two suspects.
Here’s a look at what we know and don’t know.
Known
Suspects: Police have named two brothers as suspects in the shooting. They are Cherif and Said Kouachi, 32 and 34. A third suspect, 18-year-old Mourad Hamyd, surrendered late Wednesday at a police station near the French-Belgian border.
Background: Cherif Kouachi was convicted on a terrorism charge in 2008 and sentenced to a year and a half in prison. He was part of an Islamist cell enlisting French nationals from a Paris mosque to go to Iraq to fight Americans. Cherif Kouachi himself was arrested days before he alleged planned to travel to Syria, allegedly to train.
Magazine victims: Twelve people were killed in the assault. Eight were employees of or contributors to the magazine. They included Stephane Charbonnier, the top editor, and Bernard Maris, an economist. One victim was a visitor to the magazine, and one was a maintenance worker.
Police victims: Paris police confirmed the names of two officers killed in the massacre: Franck Brinsolaro, 42, a bodyguard to Charbonnier, and Ahmed Merabet, 28, who was on patrol outside and was shot in the head by one of the attackers as they fled.
Investigation: Interior Minister Bernard Cazeneuve said that investigators had spoken to the parents of the Kouachi brothers and detained nine people.
Mosque violence: At least three mosques in France were targeted by violence Wednesday and Thursday, authorities said. One mosque near the Spanish border reported shots fired at a prayer room from outside. At another, investigators found an exploded grenade inside. There were no immediate reports of injuries.
Remembrances in France: President Francois Hollande declared a national day of mourning on Thursday. A moment of silence was observed at noon local time. Hundreds stood in the rain at Notre-Dame cathedral, and the Paris subway stopped rolling.
Around the world: The slaughter triggered an outpouring of grief and rage. People gathered at vigils in cities to defend free speech, and the hashtag #jesuischarlie — “I am Charlie” — was all over Twitter. Pope Francis offered prayers.
Washington: Attorney General Eric Holder will travel to Paris for an international meeting Sunday convened by the French interior minister in response to the attack. A White House official said that President Barack Obama would be briefed again Thursday on the search in France.
Unknown
Possible sightings: Two masked attackers with machine guns robbed a gas station northeast of Paris on Thursday. Authorities were investigating whether there was a connection to the Charlie Hebdo attack. Nearby, police officers and helicopters swarmed the town of Crepy-en-Valois.
Officer shot: A police officer was shot to death early Thursday in the Paris suburb of Montrouge, and a second was hurt. Authorities did not explicitly rule out a connection to the Charlie Hebdo attack. The Paris prosecutor’s office said that the case had been assigned to the counterterrorism unit.
Where are the suspects? The Kouachi brothers were at large Thursday. Authorities were hunting for them across France. At least two suspects escaped by car after the shooting. They were seen on video shouting “Allahu akbar!” — “God is great” — and “We have killed Charlie Hebdo!”
Training: The gunmen were armed with AK-47s, and analysts have said that they were probably highly trained, given the sophisticated nature of the weapons and the extent of the killing.
Motive and connections: A source close to the investigation told NBC News that the men targeted magazine employees who had created or published cartoons showing the Muslim prophet Muhammad, and asked for their victims by name. French authorities have not confirmed a motive. Broader connections to international terrorism are also not clear.
Jason Cumming, Alastair Jamieson and Alexander Smith of NBC News contributed to this report.