Some 160 000 people have fled their homes in Cameroon's English-speaking regions because of violence between anglophone separatists and government forces, the United Nations said on Tuesday.
"The majority of the displaced have fled into the bush with little to survive on," the UN's Office for the Coordination of Humanitarian Affairs (OCHA) said in a report.
"Others are hosted by local communities who are also grappling with adverse living conditions," it added.
The figure marks the UN's first detailed estimate of the number of people displaced since the crisis began to escalate in late 2016.
Previously the UN, encountering difficulties in accessing remote parts of the Northwest and Southwest regions, had said "tens of thousands" had left their homes.
In addition to the 160 000 internally displaced, the OCHA said 20 000 had sought refuge in neighbouring Nigeria. In contrast, Nigeria's State Emergency Management Agency (SEMA), has put the number sheltering in Cross River state alone at 34 000.
Witness accounts given to AFP in Nigeria describe Cameroonians traversing the border on foot in mountainous and densely forested areas, making crossings difficult to track.
Violence in the Northwest Region and Southwest Regions occurs almost daily, pitching armed separatists against Cameroonian government forces.
The insurgency began in 2016, when activists in the anglophone minority, comprising about a fifth of the country's population of 22 million, stepped up a campaign for greater autonomy.
President Paul Biya rejected their demands, prompting radicals to make a full-blown but symbolic declaration of independence last October 1.
On Friday, a man was abducted by gunmen in Widikum in the northwest, sources said. Clashes also took place earlier in May in Bafut and Yo-Ke.
The separatists - whose death toll is unknown - are accused of kidnappings officials and other French-speaking Cameroonians, while the army is accused of abuses and burning houses.
According to the International Crisis Group (ICG) think tank, "at least 120" civilians and "at least 43" security forces have been killed since the end of 2016.