SEOUL, March 20 (Yonhap) -- South Korea's government said a malicious code from unknown hackers caused massive computer network failures at several major TV stations and banks Wednesday, but nothing else has been determined yet, including whether North Korea was involved in the suspected cyber attacks.

Three broadcasters -- KBS, MBC and YTN, three banks -- Shinhan, Nonghyup and Jeju, and two insurance firms reported to the National Police Agency (NPA) that their computer networks were entirely halted around 2 p.m. for unknown reasons, police said. Woori Bank, a leading lender in Seoul, also came under an apparent hacking attack at the same time but managed to defend its computer networks through an internal system.