The radical Islamist group Ansaru on Sunday claimed the recent kidnapping of a French citizen in northern Nigeria, citing France's push for military intervention in Mali as a justification.
Ansaru "announces to the world, especially the French government, that it was responsible for the abduction of engineer Francis Colump, 63, working for the French company Vergnet," said a statement emailed to journalists.
Late last Wednesday some 30 gunmen stormed Vergnet's residence in Katsina state, where the alternative energy firm has a wind power project.
"The reason for his kidnap is the stance of the French government and the French people on Islam," said the statement written in Hausa, the dominant language in Nigeria's mainly Muslim north.
The group specifically pointed to "France's major role in the (planned) attack on the Islamic state in northern Mali."
It also cited France's "law outlawing the use of Islamic veil by Muslim women."
Paris has backed plans to deploy a west African force to northern Mali to flush out the Al-Qaeda-linked Islamist groups who took control of the vast desert territory earlier this year.
Last year, France passed a law banning the wearing of the full-face veil.
"We inform the French government that this group will continue launching attacks on the French government and French citizens ... as long as it does not change its stance on these two issues," the Ansaru statement said.
Ansaru is less well known than Islamist group Boko Haram, which is waging a deadly insurgency across northern Nigeria that has killed hundreds since 2009. Boko Haram has said it wants to create an Islamic state in the north.
The two groups are known to have ties but are seen as independent.
In November, Britain's interior ministry identified Ansaru as a "Nigeria-based terrorist organisation" and declared membership or support for it illegal.
The group's full name, Jama'atu Ansarul Muslimina fi Biladis Sudan, is roughly translated as "Vanguards for the aid of Muslims in black Africa."
Britain has said the group likely has ties to Al-Qaeda's north Africa franchise, Al-Qaeda in the Islamic Maghreb, and may have been responsible for the 2011 kidnapping of a Briton and an Italian in northern Nigeria. Both hostages were killed in March.
French President Francois Hollande on Friday told the Europe 1 radio station that Colump's kidnappers were "probably linked to AQIM or the groups which are today in Mali."
The police chief in Katsina, Abdullahi Magaji, told AFP that there were indications that former or current employees of Vergnet had been involved, arguing that the attack appeared to be "an inside job."
France's public prosecutor has launched a preliminary investigation into the abduction, treating it as the work of "an organised band related to a terrorist group", according to a judicial source.
Kidnappings are common in Nigeria, Africa's most populous country, but most abductions have targetted expatriates working for energy companies in the oil producing south.