Members of the French GIPN intervention police forces secure a neighbourhood in Corcy, northeast of Paris.
The eyes of France and the world are focused on rolling farmland and forest north of Paris, where cows are usually more common than automatic weapons.
Convoys of police in armored vehicles with helicopter support have swooped into rural villages, searching into the night for two brothers thought to be behind Wednesday's killing at the headquarters of the satirical magazine Charlie Hebdo.
The prime suspects in the case were spotted Thursday about 100 miles north of Paris, armed with kalashnikovs. They robbed a gas station, but then apparently abandoned their stolen car.
"They now appear to be surrounded by hundreds of crack riot police and military helicopters that have been hovering over the area," according to Vivienne Walt, Time's Paris-based correspondent. Walt says the manhunt is focused on an area of small, old towns, lined with stone walls and narrow streets.
"The police seem to have them cornered, possibly inside the houses," Walt notes. "They've been going house-to-house looking for them. Residents have told reporters that police have arrived at the front door and asked if they've seen the men. So this is really an intensive search and clearly a pretty frustrating one."
Those frustrations were interspersed with progress in the case. In a major break for police, authorities found the national identity card of the older of the two brothers, Saïd Kouachi, in the Citroen car used to flee the magazine's headquarters. Saïd Kouachi has been well known to French intelligence agents since 2003 for his involvement in extremists activities. The elder sibling was sentenced to three years in prison in 2008 for his involvement in a network sending men to fight with al-Qaeda in Iraq.
While the manhunt for the brothers continued, three major French media organizations have agreed to help fund Charlie Hebdo. And the remaining staff at the magazine say they will manage to put out a new issue next week. They say they'll print one million copies of the once-struggling magazine.