Cameroon has said it will complain to the United Nations about several recent incidents with Nigerian troops in the disputed Bakassi peninsula, one of which led to the death of a Cameroonian soldier.
Communications Minister Pierre Moukoko Mbonjo said in a statement read out on state television on Wednesday night that "serious incidents occurred in the Bakassi peninsula on Cameroonian territory on 5, 17, 18 and 21 June 2005, following repeated acts of aggression by the Nigerian armed forces."
"These incidents caused the death of a Cameroonian soldier, serious injuries and material damage," he added.
Nigeria, which originally denied that its security forces had been involved in any skirmish in the Bakassi peninsula, softened its position on Thursday by saying that it had agreed to investigate the incidents and punish those responsible.
Remi Oyo, the official spokeswoman for Nigerian President Olusegun Obasanjo said in a statement: "President Obasanjo and President Biya have spoken on the issue and agreed that a full investigation of the incident in which the soldier was reportedly killed on June 17, 2005, was required to correctly identify the real culprits and bring them to justice."
Earlier this week, a Nigerian military spokesman had dismissed the incidents as clashes between Cameroonian troops and Nigerian fishermen who, he said, were frequently harassed by the Cameroonian authorities."
The 1,000 square km territory is inhabited by about 10,000 fishermen.
The Cameroonian government said the latest incidents in the Bakassi peninsula constituted a "flagrant violation" of a 2002 ruling by the International Court of Justice in The Hague. This awarded the potentially oil-rich Bakassi peninsula to Cameroon and ordered Nigeria to withdraw completely from the swampy finger of forested land that juts into the Gulf of Guinea.
"In the face of these repeated acts of aggression and provocation by Nigerian armed forces, His Excellency Paul Biya, President of the Republic of Cameroon, has decided to refer the matter to the United Nations," the statement said.
The state-owned Cameroon Tribune newspaper reported on Thursday that the government would report the incidents to the UN Security Council.
Nigeria originally agreed to withdraw its troops from the Bakassi peninsula by 15 September 2004, but it missed this deadline and has been stalling on its commitment to hand over the territory ever since.
Cameroon issued its strongly worded statement on the latest border clashes following talks on Monday between President Biya and a special envoy from Abuja, Owo Labi, Nigeria's High Commissioner to the Economic Community of West African States (ECOWAS).
"The brutal and unilateral attacks and provocations by Nigerian troops, which forced the Cameroonian army to retaliate in self-defence, are causing fears of further delays in the process of withdrawal and transfer of authority in the Bakassi peninsula and constitute a threat to peace and security in the area," it said.
Cameroon and Nigeria came to the brink of war over the Bakassi peninsula in 1981 and again in the mid-1990s.
Some of Nigeria's most prolific offshore oilfields are situated near the peninsula. Whoever ends up controlling the scrap of territory will also control potentially oil-rich offshore waters that have so far been off-limits for exploration because of the territorial dispute.
Nigeria failed to send a delegation to a session of a UN-supervised mixed commission on the border dispute which had been due to take place in Yaounde from 10 to 15 June.