Bakassi residents to pay tax under Cameroon sovereignty
Cameroon has formally taken full sovereignty of the oil-rich Bakassi peninsula, ceded by Nigeria in 2008.
The territory was handed over after an International Court of Justice ruling, ending years of border skirmishes.
The five-year UN-backed transition period exempted residents in the area, many of them Nigerian fishermen, from paying tax.
Now the Nigerians must also apply for a residence permit or take up Cameroonian citizenship if they wish to remain.
The BBC's Randy Joe Sa'ah in the capital, Yaounde, says official figures put the number of people living in the peninsula at 300,000, 90% of whom are Nigerian.
It is not clear how many have decided to leave the region, but it is believed most have decided to remain, he says.
Most of those who have left Cameroon are living in camps in Nigeria's Cross River state, where they have been critical of the authorities for not doing enough to resettle them.
It was agreed that the transitional phase would allow Cameroon to develop an administrative presence in the 1,000sq km (386 sq mile) area, which juts into the Gulf of Guinea.
For Nigerians refusing to change nationality, a residence permit will cost 130,000 CFA ($260; £170) for two years or 250,000 CFA for 10 years, our reporter says.
However, the main concern for Bakassi residents is the prospect of paying taxes, he says.
In Nigeria, small businesses and road-side stall holders do not have to pay tax, but this is not the case in Cameroon, our reporter says.
Each area is targeted once a year by officials working for the Ministry of Finance accompanied by paramilitary police in order to recover taxes from all businesses, no matter their size, he says.
Our reporter says most Bakassi fishermen take the fish over the border to Nigeria, but they will now be liable to pay some form of customs or export tax.
With the area coming under full Cameroonian control, some residents have also said they fear harassment from the paramilitary police, or gendarmes.
One of the traditional rulers of Bakassi, Etim Okon Edet, expressed his dismay over the move.
"I think the spirit of everybody is down. The people of Bakassi, apart from being Nigerians, they are also citizens of the world, and they needed the protection of the world, which they hadn't seen," he told the BBC's Newsday programme.
He said residents were fed up talking about the issue and as far as they could see, the ceding of the territory was because "they were just interested in the oil".
"We have given them the oil, we have also given them the land, so we should be allowed to have our peace."
According to the AFP news agency, large sections of the area have been gazetted for exploration, but energy firms have stayed clear of the region. Its offshore waters are thought to contain substantial oil and gas reserves
In the last five years, Cameroon was meant to have started developing the area, building clinics, schools and roads in the peninsula.
But a recent government inspection revealed that some of the projects had floundered, revealing dry boreholes and half-completed buildings abandoned because of mismanagement and poor contractors, our reporter says.
Residents have also appealed for help from the government to build some sort of barrier to stop rising flood waters in coastal areas, he says.
The two countries nearly went to war over Bakassi in 1981 and bloody clashes claimed 34 lives in 1994.
That year, Cameroon took Nigeria to the International Court of Justice in The Hague, which ruled in favour of Yaounde in 2002.
Nigeria rejected the ruling, but the UN intervened and the two countries set up a UN-chaired joint commission to resolve the conflict.
The peninsula was administered by Nigeria from independence in 1960. However, Cameroon based its claim of sovereignty over the region on maps dating back to the colonial era.