South Korea has secured technologies to build a non-lethal graphite bomb which can paralyze the North's power systems in case of war, Yonhap quoted military sources as saying on Sunday.

The so-called "blackout bomb" works by spreading chemically treated carbon graphite filaments over electric facilities to short-circuit and disrupt the power grid.

The weapon has been developed by the Agency for Defense Development as key part of South Korea's pre-emptive strike program called Kill Chain.