One of the two brothers suspected of attacking the offices of Charlie Hebdo traveled to Yemen, where he likely received training in a camp run by al Qaeda in the Arabian Peninsula (AQAP). Said Kouachi is believed to have traveled Yemen in 2011, according to multiple press outlets.
Citing a "senior American official" who spoke with the media, The New York Times reports that Said trained for "a few months" on small arms. CNN adds that it "is also possible Said was trained in bomb making, a common jihadist training in Yemen."
Video footage of the attack made it clear early on that the attackers had received training. [See LWJ report, Terrorists who attacked French magazine displayed professional training.]
Said and his younger brother, Cherif Kouachi, are the two principal suspects named by French officials.
The attackers reportedly claimed that they were sent by al Qaeda. "You can tell the media that it's al Qaeda in Yemen," one of the terrorists said during the assault, according to a witness cited in the press. Al Qaeda in Yemen is a reference to AQAP, al Qaeda's official branch in Saudi Arabia and Yemen.
At least one other witness has corroborated this account, saying the jihadists claimed allegiance to al Qaeda.
AQAP has explicitly threatened Charlie Hebdo and its editor-in-chief, Stephane Charbonnier, who was killed in the attack.
The 10th issue of AQAP's Inspire magazine, which was released in early 2013, includes a "Wanted" poster that is headlined, "Dead or Alive For Crimes Against Islam." The poster is intended to encourage followers to shoot 11 people, all of whom have supposedly offended Islam. One of them is Charbonnier.
A French official who briefed the press shortly after the attack also claimed that the terrorists are "linked to a Yemeni terrorist network."
Thus far, no terrorist organization has claimed responsibility for the attack. Al Qaeda and Islamic State supporters have both praised the terrorists responsible. Twitter accounts linked to AQAP have portrayed the massacre as being consistent with the types of attacks the group has advocated in the past.