Hundreds of South Koreans headed to North Korea on Sunday to meet relatives they haven't seen for more than six decades in family reunions taking place amid improved inter-Korean relations. A total of 357 people departed from the eastern port city of Sokcho and were to arrive at Mount Kumgang, a scenic resort on the North's east coast, later Sunday for three days of reunions with 88 relatives from the North. The meetings are the second set of reunions in a week. On Saturday, 82 elderly South Koreans, accompanied by 58 family members, came back from the North's mountain resort after three days with their long-lost loved ones. "Assuming my brother was dead, I have held memorial services for him for a long time. I am so happy that I can see him," said Lee Oh-soon, the oldest South Korean participant scheduled to meet with her 83-year-old younger brother. "I'm so grateful to him for being alive."    The latest reunions, the first since 2010, suggest that relations between the two Koreas are improving after high tensions last year over the North's third nuclear test and its threats of war against the South and the United States. South Korean President Park Geun-hye first proposed a resumption of family reunions in a New Year's news conference last month, saying it could be a first step toward better relations. The North first balked at the idea, but later agreed to resume the reunions and set dates. Pyongyang demanded at the last-minute, however, that the South postpone planned annual military exercises with the U.S. until after the reunions, saying the meetings could not take place when such drills were under way. The North has long denounced the drills as a rehearsal for invasion. But Pyongyang later backed down and agreed to hold the reunions as planned in high-level talks that the two sides held earlier this month for the first time in seven year. They also agreed to stop slandering each other and work together for better ties. The North's concession is a stark contrast to the harsh war threats that the provocative regime churned out almost every day during the "Key Resolve" and "Foal Eagle" exercises last year, sparking fears of armed clashes or even war on the divided peninsula. The softer stance could suggest Pyongyang is serious about improving inter-Korean ties as leader Kim Jong-un called for in his New Year's message, though critics remain suspicious that the charm offensive could be a deceptive prelude to provocations. This year's military exercises are set to kick off on Monday. On Sunday, the North's main Rodong Sinmun newspaper accused the South of violating the high-level agreement to stop slander against each other, citing Seoul's mentioning of the North's human rights issue, press reports critical of the North and the South's plan to continue psychological warfare operations against the North. "Should the South Korean authorities truly want an improvement in North-South relations, they should make the decision to stop slander that increases mutual misunderstanding and distrust and stirs up hostile feelings," the newspaper said in a commentary. Millions of Koreans remain separated across the border as the sides are technically in a state of war after the three-year Korean War ended in a cease-fire, not a peace treaty. There are no direct means of contact between ordinary civilians of the two countries. Family reunions are a pressing humanitarian issue on the divided peninsula, as most of the separated family members are in their 70s and 80s, and wish to see their long-lost relatives before they die. More than 129,200 South Koreans have applied for temporary reunions with their family members and relatives in North Korea since 1988, according to government data. Among them, more than 57,700 people, or 44.7 percent of the applicants, have died, according to the data. South Korea has repeatedly called for frequent family reunions with North Korea. Pyongyang, which has used family reunions as a bargaining chip aimed at extracting economic aid and other concessions from the South, is negative about regularizing reunions.