The NDI is holding similar events in Takeo province’s Tropeang Thom Khang Cheung commune, on Wednesday, and Kratie province’s Svay Chreas commune, on Friday.
Thousands of district positions to be contested in June 4 ballots.
Depending on the source, 81.47 percent to 95 percent of Cambodia's 9.6 million eligible voters are registered.
Congressman Alan Lowenthal says U.S. Congress is concern over the arrest of opposition activists and officials in Cambodia.
The two-week campaign period will conclude on June 2, two days before the vote on June 4.
Almost 8 million people have registered to vote in the forthcoming commune council elections on June 4.