No specific figures have so far been provided by the agency.
About 70 percent of all North Korean submarines went onto the sea, South Korea's YTN news channel reported.
The news came just a day the conflicting neighbors held the first round of high-level talks to reduce tensions that escalated earlier this week. Earlier in the day, local media reported that Seoul and Pyongyang would continue high-level talks later Sunday.
The episode was the first major armed confrontation between the neighbors in five years, and came in the wake of Seoul’s resumed broadcasting of military propaganda over the border toward North Korea, a practice it gave up a decade ago. Under the North Korean ultimatum, Saturday was the last day for Seoul to terminate its broadcasting.