France observed a national day of mourning Thursday following one of the bloodiest days since the end of World War II. Thousands rallied in Paris at the feet of the darkened Eiffel Tower and in countless cities across the country. As France wept, nearly 90,000 law enforcement personnel pursued Said and Cherif Kouachi, the gunman who attacked Charlie Hebdo's headquarters. The two men were spotted by a gas-station manager near Villers-Cotterets, northwest of Paris on Thursday morning. Later, they were reportedly seen in Longpont before walking into the forest of Retz, which covers 32,000 acres (an area larger than Paris). French officials say nine people are in police custody in connection to the attack. The teenage driver of the Kouchai brothers turned himself in last night.