Hundreds of soldiers in the Democratic Republic of Congo have gone on the rampage after finding one of their colleagues hacked to death.
Mbandaka has been relatively peaceful since the war officially ended in 2003.
Extra troops had to be deployed in the western town of Mbandaka, when the soldiers swept through the town, beating up civilians and looting homes.
Provincial governor Yves Mombando-Yogo told the BBC that loyalist troops had chased the renegades back to barracks.
The rampaging troops were integrated into the army after civil war ended.
They used to belong to one of the militias fighting in the volatile north-eastern Ituri region.
"When they found their colleague dead, they broke into the armoury, stole the weapons and started pillaging," Albert Donatien Bekalola, Mbandaka's mayor, told Reuters news agency.
He said that four people had been shot dead by the rioting troops.
UN spokesman Kemal Saiki said the rampage had lasted for several hours.
There is no indication of why the soldier had been killed.
Correspondents say Mbandaka has been relatively peaceful since the Congolese war officially ended in 2003, while armed groups have continued to roam parts of the east.