He said the others were 10 police and three civilians but he did not know why they also had been taken away by the government soldiers.
Refugees at Kibati are among 250,000 people driven from their homes by the latest round of a rebellion that erupted in August in eastern Congo.
A UN spokesman did not have any immediate comment on the incident as it was not clear why the men were on the convoy.
UN convoy stoned
Some refugees blame the UN for their plight, in failing to protect them from atrocities they say were committed by both rebels and government troops.
Bahati, a Goma resident, said: "The enemy was arrested here at this checkpoint and their guns were found in the Monuc vehicles, Monuc are the ones bringing problems to Congo not the citizens."
Congolese at Kibati camp hurled stones at the UN convoy and at journalists accompanying it, as they have done several times before in the past few weeks.
The 17,000 Congo peacekeepers whose primary mandate is to protect the local people, are badly overstretched, the UN said, and it has approved deployment of at least 3,100 reinforcements.