Parents of children killed when a passenger ferry sank last month led a somber march on South Korea's presidential palace in the early hours of Friday morning, where they demanded to meet with President Park Geun-hye.

Clutching memorial portraits of their children, family members and grieving parents were prevented by riot police from nearing the palace, and instead sat in the middle of the road where they sobbed, wailed and shouted in anger.

"Listen to us, President Park. Just give us 10 seconds!," one family member said, using a portable address system. "Why are you blocking the way?," said another. "President Park, hear our voices!"