SEOUL (AFP) - North Korea kept its border with South Korea closed for a second consecutive day Saturday, stranding hundreds in the North, officials here said. A South Korean and four foreigners, including three Chinese and an Australian, were allowed to return to the South from Kaesong, a Seoul-funded estate just north of the border, a unification ministry spokesman said. But more than 420 others were not allowed to do so. The South Korean woman who was given permission to travel to the South was getting married on Sunday, the spokesman added. "The five people returned to the South this morning but there is no word from the North about other cross-border trips to and from Kaesong," the spokesman told AFP. "We've been urging the North to reopen the border," he said. On Monday the communist country switched off military phone and fax lines, which are used to approve border crossings, denouncing an ongoing annual US-South Korean military exercise, which it sees as a rehearsal for invasion. The North reopened the frontier without explanation a day later but kept the lines switched off, requiring the exchange of hand-delivered letters to approve crossings. On Friday the North did not respond to South Korean calls for such approvals, the ministry said. The North Monday put its 1.2 million-member army on combat alert in response to the military drill south of the border. It says the exercise involving tens of thousands of troops is aimed at launching a "second Korean War" while Seoul and its ally Washington insist it is a routine annual defensive drill.