The four victims were sexually abused between 2014 and 2015, spokesman Farhan Haq told reporters.
The UN mission in the Central African Republic has been hit by a wave of allegations of sex abuse by its peacekeepers, whose mandate is to protect civilians in the strife-torn country.
"These four allegations involve peacekeepers from the Democratic Republic of Congo," he said.
UN officials received information about the allegations from aid groups on February 11 who reported that the four minors were living at Ngakobo camp, in the Ouaka prefecture of the Central African Republic.
The Kinshasa government was notified on Monday about the allegations and now has ten days to decide whether it will carry out its own investigation of the soldiers or ask the United Nations to take the lead.
After rape allegations targeted troops from the DR Congo last year, the United Nations had decided to send the full contingent of some 120 soldiers back home.
Ban last week appointed a special coordinator, American Jane Holl Lute, who will be tasked with improving the UN response to sexual abuse cases involving peacekeepers.
French and European Union soldiers serving in the Central African Republic also face allegations of sexual abuse, although their missions are not under the UN flag.
In most of those cases, the young girls and boys were offered food in exchange for sex.
