In the 18th century, Thailand officially annexed the former Cambodian province of Surin.
The only other Cambodian province to border Svay Rieng is Prey Veng.
A spokesman was quoted by Reuters as saying that the faction would be sending representatives to seven Cambodian provinces to work with UN peacekeeping forces.
Generally people from Sihanoukville are friendly and they are used to visitors from other Cambodian provinces and foreigners.
In the southern Cambodian province of Kampot, unidentified gunmen ambushed a train on Saturday, killing three people.
A number of Mnong live in the eastern Cambodian province of Mondulkiri.
Phnom Santuk is a hill and cultural site in the Cambodian province of Kampong Thom.
At least recently, the tree is an important firewood source in some areas of the Cambodian province of Kompong Chhnang.
Numbering about 25,000, the Tampuan people live in the mountainous Southern and Western portions of the Cambodian province of Ratanakiri.
The group held the three foreigners and several Cambodians under "miserable conditions" at Vine Mountain rebel base in the southern Cambodian province of Kampot.