* Cocoa-growing areas frequently hit by disputes over land
* Farmers driven off illegal plantations in forest reserves
* Areas will hit peak production in coming months
GUIGLO, Ivory Coast, Oct 9 (Reuters) - An ethnic-fuelled land dispute has driven thousands of farmers off illegal plantations in Ivory Coast's main cocoa belt, threatening the start of the harvest in the world's top producer.
Humanitarian workers and local government officials said at least 3,000 people had already been displaced by the violence, after the government said last week that two people had been killed in clashes and soldiers had been sent to the area.
Ivory Coast's main production area has for decades been subject to explosive disputes over land ownership between native groups in the area and migrants from neighbouring countries and other parts of Ivory Coast.
The latest dispute broke out last month between members of the We alliance from the Guere, Yacouba and Wobe ethnic groups, who entered the Cavally and Gouin-Debe forest reserves in western Ivory Coast and threatened ethnic Baoules and migrants from Burkina Faso farming there.
"They threatened to kill us if we didn't leave the village within 10 minutes," said Gouin-Debe cocoa farmer Pierre Koffi Kouame. "There are around 30 small villages in the area where we live and all of them were visited by these youths.
"We don't do anyone any harm. We just grow cocoa," he said.
The 2017/18 cocoa season in Ivory Coast began on Oct. 1 following a record harvest of over 2 million tonnes last season. Most growing areas will hit peak production within the next three months.
"The cocoa is already there and many pods are ripe and should have already been harvested last week," said Sylvain Kouadio, who fled his plantation near the town of Blolequin late last month.
"If nothing is done, the cocoa is going to rot. It must not stay on the trees too long."
The Ivorian Parks and Reserves Office (OIPR), which manages protected land, estimates that up to 40 percent of Ivorian cocoa production comes from illegal plantations.
Cocoa farmers have illegally set up plantations within Ivory Coast's national parks and forest reserves for decades, but the phenomenon accelerated during and after a decade-long political crisis and civil war, which ended in 2011.
Tensions over land ownership were a major factor contributing to the political crisis, and western cocoa growing areas saw some of the worst violence during two civil wars in 2002-2003 and 2011.
A Reuters reporter saw hundreds of families, recently pushed out of the forests, camped out on the premises of a local government building in the town of Guiglo, seeking to shelter their children and meagre belongings from the rain.
A local government official said those displaced from the forests typically stay for three or four days while they look for a new place to live.
"All we want is to take back our land from the outsiders who have occupied it for years," said Rigobert Toualy, a member of the We alliance in Guiglo. (Writing by Joe Bavier; Editing by Susan Fenton)