At least one of the shooters who attacked the offices of the French satirical newspaper Charlie Hebdo in Paris on Wednesday and killed 12 people had previous ties to an al Qaeda-linked terror network, according to media reports. Cherif Kouachi, one of the men wanted by French police in connection with the attack, had been sentenced to three years in prison in 2008 for his involvement in the so-called 19th arrondissement network, an al Qaeda-affiliated French group named after the district in Paris where it was based.

French police had earlier named brothers Said Kouachi and Cherif Kouachi, both in their early 30s, and Hamyd Mourad, an 18-year-old who surrendered early on Thursday, as suspects in the attack. The Kouachi brothers were born in Paris and are of Algerian descent, French police officials said on Wednesday. Both of them had also returned from Syria last year, according to media reports. Details about Mourad's background are yet unclear.

Although at this moment it is not entirely clear which militant group the attackers belonged to, or whether the incident was a “lone-wolf” attack, Cherif’s past connections to al Qaeda point toward the possible involvement of the group, which has, on several occasions, reportedly threatened the magazine’s cartoonists.

Moreover, according to media reports that cited eyewitnesses, the attackers had allegedly claimed that they belonged to “al Qaeda in Yemen,” possibly referring to al Qaeda in the Arabian Peninsula (AQAP), which is al Qaeda's official arm in Saudi Arabia and Yemen. AQAP is believed to be currently headed by Nasser Abdul Karim al-Wuhayshi, a former apprentice of Osama bin Laden.

According to a report by The Associated Press (AP), a French police official, speaking on the condition of anonymity, had also said that evidence suggested that the Paris attackers were linked to “a Yemeni terrorist network.”

However, because one of Cherif’s former associates -- a Tunisian national named Boubaker el Hakim from the 19th arrondissement network -- had appeared in an ISIS propaganda video in December last year, the two brothers could also have possible links to the Islamic State group.

According to a report by the SITE Monitoring Service, Afriqiyah Media -- believed to be a pro-ISIS media group -- had on Wednesday released a statement praising the “highly professional” attacks in Paris.