Paris Terror Attacks: France Hunts Potential 'Accomplices' in Deadly Attacks

— -- French authorities are racing today to find possible "accomplices" of the gunman who killed five people, including a police officer, as part of the dual terror attacks in Paris last week, French Prime Minister Manuel Valls said on French television.

"We think Coulibaly had probably accomplices... The threat is still present," Valls said, echoing concerns of U.S. security experts that the extremists who killed a total of 17 people last week in Paris may not have worked alone.

Valls' comments come a day after a video emerged online which shows one of the gunmen, Amedy Coulibaly, pledging his allegiance to the leader of the Iraqi terror group ISIS and claiming his actions are "totally justified." In the video, Coulibaly shows off an arsenal of several firearms and at one point wears what appears to be a ballistics vest.

Coulibaly was killed in a hostage rescue operation Friday, after investigators say he murdered a policeman and then four other people in Paris. On Wednesday, two other alleged terrorists, brothers Cherif and Said Kouachi, opened fire on the satirical French magazine Charlie Hebdo, killing 12, including two police officers. The Kouachis were also killed in a raid by authorities Friday after a tense standoff elsewhere in Paris Friday.

Overnight Parisian officials said they identified the apartment in the Gentilly suburb of Paris where Coulibaly stayed shortly before the attack. The local mayor told ABC News Coulibaly rented the place just a week before his violent attacks.

Before their deaths, both Coulibaly and one of the Kouachis reportedly spoke with a French television station in the midst of their separate standoffs with police. Cherif Kouachi claimed they were part of al Qaeda's Yemen-based affiliate, AQAP, and had received funding from the terror group during trips to Yemen. U.S. officials said it appears at least one of the brothers received firearms training from the terror group.

Over the weekend a senior U.S. intelligence official told ABC News the French terror attacks, specifically the Charlie Hebdo assault, were carried out with the support of an unknown number of "enablers" from some form of jihadi network that reached into Syria and Yemen. Morten Storm, a former jihadi who spied on AQAP for years for Western intelligence, told ABC News last week he suspected such a network was involved in the massacre.

Cherif Kouachi declined to answer when reporters at the French TV station asked if any other people were involved in their assault on Charlie Hebdo. Coulibaly spoke to the same station and claimed he was a member of ISIS -- generally thought to be a rival terror group to al Qaeda -- and claimed he had "synchronized" his attack with the Kouachis.

Law enforcement agencies as far away as New York are also taking extra precautions today, as another video posted by a jihadi supporter Sunday renewed calls for attacks on Westerners, including on police and soldiers.

Authorities are also still chasing a woman identified as the girlfriend of Coulibaly, who left Paris early last week before the attacks began and is now believed to have crossed from Turkey into Syria.

ABC News' James Gordon Meek and Lee Ferran contributed to this report.