KANO, Nigeria: Nigerian police said Friday that a French citizen kidnapped in the north may have been taken by employees of his company after France's president suggested Al-Qaeda was involved.

An engineer with the French firm Vergnet was abducted late Wednesday by a group of 30 gunmen in Katsina state who stormed and opened fire on the residence where he was staying. Two Nigerians died in the attack.

"In looking at the way the operation was carried out, in terms of coordination, speed and expertise, all indications are it was an inside job," Katsina's Police Commissioner Abdullahi Magaji told AFP.

"Our initial suspicion is that it could be the work of former or current employees of the company," he added.

Kidnap for ransom is common in Nigeria, but such incidents have typically involved expatriates working for energy companies in the oil-producing south.

Radical Islamist group Boko Haram has carried out waves of attacks in the north and has been blamed for abducting foreigners but their involvement in kidnappings remains unclear.

"The kidnap was not the handiwork of Boko Haram, as is being speculated," Magaji said.

French President Francois Hollande earlier Friday told the Europe 1 radio station that the attackers were "probably linked to AQIM (Al-Qaeda in the Islamic Maghreb) or the groups which are today in Mali."

AQIM has not been known to operate directly in Nigeria, despite being rumoured to have ties with Boko Haram.

There has similarly been no confirmation of an attack in Nigeria by forces linked to the Islamist rebels who control northern Mali.

Katsina state has a border with Niger and to the west of Niger lies northern Mali.

Nigeria's army spokesman Major General Bola Koleoso refused to comment on Hollande's suggestion of an Al-Qaeda or Mali link in the attack.

Magaji said it was clear the attackers knew the area well, arguing that it was therefore unlikely "foreigners" were involved.