A group of nine North Koreans crossed the tense western sea border into South Korea last week, officials said Wednesday, the latest in a string of defections that could further complicate inter-Korean relations. The defectors waved their hands aboard an engineless boat and expressed their wish to defect last Saturday when spotted by South Korea\'s military, the officials said on the condition of anonymity. The nine North Koreans include three adult men, two adult women and four children, suggesting that they may be family members. The North Koreans are being questioned by South Korean officials about their motives and their defection route, the officials said. The development comes amid lingering tensions over the North\'s two deadly attacks on the South last year that killed a total of 50 South Koreans, mostly soldiers. \"The defection could have negative influences on inter-Korean relations,\" said Kim Yong-hyun, a North Korea expert at Dongguk University in Seoul. He also said it could illustrate the severity of chronic food shortages and economic difficulties in the North. The impoverished North has vowed to build a prosperous and powerful nation next year, the centennial of the birth of the country\'s late founder, Kim Il-sung, but it has made a series of appeals for food assistance from the international community. The latest defection came four months after a group of 31 North Korean fishermen drifted aboard a troubled wooden vessel across the tense western sea border. Seoul has since repatriated 27 of them to the North while allowing the other four to remain in the South in accordance with their wishes.However, the North claimed that South Korea kidnapped the 31 North Koreans and accused the South of forcing the four who wished to stay into defection, a charge denied by Seoul. Pyongyang also called for talks with South Korea to discuss the repatriation of the four North Koreans, though no meeting was held. More than 21,000 North Koreans have defected to the South to avoid chronic hunger and political oppression since the 1950-53 Korean War ended in a cease-fire.