They petition parliament before police disperse the procession.
A Cambodia-based rights group is being denied access to opposition figures held at a prison in Phnom Penh.
Soldiers move against villages to add property to a retired veterans' commune.
The police chief of Siem Reap province says the 26-year-old has confessed to making threats on social media.
They accuse companies, the government and military of encroaching upon their land.
But some fear further government control over what people may choose to see.
The government says change is already underway, but ‘will take time.’
Rights groups and villagers say the Vietnamese-run mine is protected by local authorities.
They say the summons was meant to threaten challengers to a Vietnamese rubber company.
They are up in arms because their factory is firing workers and pregnant women without cause.
Their problems have been complicated by suspicions that forestry officials are colluding with illegal loggers.
They say local authorities in Battambang province’s Rotanak Mondol district have taken the money they are due from a company building a dam on their land.
Community members, including several local officials, have harvested timber in defiance of written pledges.
Authorities could not control heavy water flows once the dam operators released the floodgates.
Interior Ministry spokesman says anti-government protests were equally to blame for the killing.
The Ministry of Interior has set a three-month deadline for them to leave or be deported back to Vietnam.
The indigenous residents say the water is causing skin disease that has hit children hardest.