By Prak Chan Thul
PHNOM PENH (Reuters) - A Cambodian opposition MP was jailed for two and a half years on Monday for posting a map on Facebook professing to show that the government had ceded territory to Vietnam.
Cambodia has for centuries fretted about its much bigger neighbors - Vietnam to the east and Thailand to the northwest - encroaching on its territory. The issue remains emotive and many Cambodians are suspicious of both countries.
Phnom Penh Municipal Court found Um Sam An, 40, of the opposition Cambodia National Rescue Party (CNRP), guilty of incitement to cause discrimination and instability when he repeatedly posted "fake" border maps on Facebook.
"Um Sam An's crimes caused severe social instability and is a racial incitement," judge Heng Sokna said in his verdict. Sam An was also fined $1,000.
Sam An was arrested in April after arriving from overseas amid what activists say is a crackdown on critics of Prime Minister Hun Sen ahead of local and general elections.
Another CNRP senator, Hong Sok Hour, is in prison awaiting trial on a charge of posting on Facebook a fake government pledge to dissolve Cambodia's border with Vietnam.
(Editing by Nick Macfie)