"What you have seen today is just the beginning of a long campaign, " says political activist Kim Min Sik.

CNN: Pains from the Past

"We do not rule out the possibility of North Korea being involved, but it's premature to say so, " Defence Ministry spokesman Kim Min-seok said.

BBC: South Korea network attack 'a computer virus'

The second controversial match took place about an hour later, pitting South Korea's Ha Jung-eun and Kim Min-jung against the Indonesians Meiliana Jauhari and Greysia Polii.

CNN: STORY HIGHLIGHTS