In this photo from May, South Korean soldiers look at the North Korean side through binoculars at an observation post in the demilitarized zone that has separated the two Koreas since the Korean War. (Lee Jin-man/Associated Press)North Korea and South Korea have agreed to hold a new round of reunions next month for families separated during the Korean War in the 1950s.

Red Cross officials from the two sides reached an agreement that about 200 families who have had no contact with relatives on the other side of the border will be allowed to spend several days together in September.

This agreement is the latest sign of warming relations between the two Koreas, despite the North's continued impasse with the international community over its nuclear weapons program.

A previous series of reunions allowed 1,600 families to visit one another, but the program was cancelled by Pyongyang two years ago over some of the hardline policies of newly elected conservative South Korean President Lee Myung-bak.

In another conciliatory gesture Friday, North Korea said it will free four South Korean fishermen detained last month after their boat accidentally strayed into northern waters.

The fishermen and their boat will be handed over to South Korean authorities across the eastern sea border at 5 p.m. local time Saturday, said Seoul's Unification Ministry spokesman Chun Hae-sung.

Millions of families were separated by the Korean War, which ended in 1953 with a ceasefire, not a peace treaty. No mail, telephone or email exchanges exist between ordinary citizens across the Korean border.

With files from The Associated Press