At least 20 M23 militants have been killed by Congolese forces since the end of January this year.
Two Congolese soldiers have also lost their lives during such clashes.
According to a statement by the head of military operations in North Kivu, General Leon Mushale, 25 other rebels have been captured while others surrendered in clashes which left six soldiers injured.
M23 rebel group mutinied against the Democratic Republic of Congo in 2012, accusing the government of failing to respect a 2009 peace deal.
The militia was defeated the following year, and hundreds of fighters fled the country.
But in January, the Congolese government and numerous witnesses said former M23 rebels were spotted in the North Kivu village of Rutshuru, having crossed over from neighbouring Uganda.