French tourists seized in Cameroon near Nigeria border
Seven French tourists have been kidnapped by gunmen in Cameroon, near the border with Nigeria, French President Francois Hollande has said.
He says they belong to the same family and were seized by a "known terrorist group based in Nigeria".
Mr Hollande added that the seven - including four children - were probably taken to northern Nigeria. Cameroon's government later confirmed this.
France urged all its nationals in the area to leave as quickly as possible.
The French foreign ministry said on its website citizens were "officially advised not to go to the far north of Cameroon (the shores of Lake Chad in the South Maroua), and the border with Nigeria, until further notice".
Mr Hollande said the Nigerian Islamist group Boko Haram may have been behind the kidnapping.
"I see the hand of Boko Haram in that part of Cameroon, and that is worrying enough for us to mobilise," Mr Hollande said.
He said everything possible was being done to rescue the family and warned other French nationals in northern Cameroon to avoid "exposing themselves".
The family had been returning from a visit to Waza National Park when they were attacked by men on motorcycles, Cameroonian officials said.
The incidents come amid a French-led intervention against Islamist militants in Mali.
At least eight French nationals were already being held by Islamist groups in Africa.
"If everything is confirmed, this signifies that the fight against terrorist groups is a necessity," said French Foreign Minister Laurent Fabius, quoted by the Associated Press news agency.
"There is a battle to be led by the international community against terrorist groups and narco-terrorists."
Boko Haram has staged many attacks across northern Nigeria in recent years, targeting churches, government buildings and the security forces.
Another Islamist group- Ansaru - is also active in the region.
On Sunday, Ansaru claimed the abduction of seven foreign workers in Nigeria.
Italian, British, Greek and Lebanese workers are thought to be among those held after an attack on a construction project in Bauchi state.
Ansaru also says it is holding a French national, Francis Colump, who was seized in the northern state of Katsina.