PARIS (AP) - French police officials identified three men as suspects in a deadly attack against newspaper offices that killed 12 people and shook the nation on Wednesday.
Two officials named the suspects as Frenchmen Said Kouachi and Cherif Kouachi, who are brothers and in their early 30s, as well as 18-year-old Hamyd Mourad, whose nationality wasn't immediately clear.
One of the officials said they were linked to a Yemeni terrorist network. A witness of Wednesday's shootings at the offices of weekly satirical newspaper Charlie Hebdo said one of the attackers told onlookers, "You can tell the media that it's al-Qaida in Yemen."
The officials spoke on condition of anonymity because they weren't authorized to publicly discuss the sensitive and ongoing investigation. No arrests have been confirmed in the hunt for the attackers.
Masked gunmen stormed the offices of Charlie Hebdo, which caricatured the Prophet Muhammad, methodically killing 12 people, including the editor, before escaping in a car. It was France's deadliest terrorist attack in half a century.
U.S. Sen. Lindsey Graham, R-S.C., told a CNN reporter Wednesday about the events in Paris and said journalists in America should be concerned.
"People in your business need to be concerned," Graham said. He said the concern is based on common sense and not any specific intelligence reports.
Graham, a member of the Armed Services Committee, also said that he "would be shocked" if the attack wasn't at least inspired by Islamic State terrorists.
He also suggested that the terror threat for the U.S. should be raised immediately.
"Copycats are likely and I am convinced there are people already in our homeland ready to do attacks like this," Graham said.
Cherif Kouachi was convicted in 2008 of terrorism charges for helping funnel fighters to Iraq's insurgency and sentenced to 18 months in prison.
During Cherif Kouachi's 2008 trial, he told the court, "I really believed in the idea" of fighting the U.S.-led coalition in Iraq. He said he was motivated by his outrage at television images of torture of Iraqi inmates at the U.S. prison at Abu Ghraib.
Shouting "Allahu akbar!" as they fired, the men also spoke fluent, unaccented French in the military-style noon-time attack on Charlie Hebdo, located near Paris' Bastille monument. The publication's depictions of Islam have drawn condemnation and threats before - it was firebombed in 2011 - although it also satirized other religions and political figures.
President Francois Hollande said it was a terrorist act "of exceptional barbarism," adding that other attacks have been thwarted in France in recent weeks. Fears have been running high in France and elsewhere in Europe that jihadis returning from conflicts in Syria and Iraq will stage attacks at home.
Associated Press writers Samuel Petrequin, Angela Charlton, Sylvie Corbet and John Leicester in Paris; Sarah el-Deeb in Cairo; Zeina Karam and Diaa Hadid in Beirut; and Aya Batrawy in Dubai, United Arab Emirates contributed to this story.