SEOUL, South Korea — South and North Korean troops exchanged gunfire across their tense border on Sunday, even as the South reaffirmed its desire to hold high-level talks with the North.

Ten North Korean soldiers approached the military demarcation line near Paju, north of Seoul, several times on Sunday, prompting South Korean border guards to broadcast warnings for them not to come any farther south, said a South Korean military spokesman, who spoke on the customary condition of anonymity.

The last time the North Korean troops approached the line, around 5:40 p.m. on Sunday, South Korean troops fired warning shots, and that prompted a brief exchange of fire between guard posts on the two sides, the spokesman said. No casualties were reported.

The military demarcation line lies within the two-mile-wide demilitarized zone that bisects the Korean Peninsula.