North Korea today announced that it will scrap an agreement aimed at preventing accidental naval clashes with South Korea, amid rising tensions over the sinking of a South Korean warship. <br/><br/>In a statement, the North Korean military has said the country would completely nullify the bilateral agreement that was concluded to prevent a contingent clash in the Yellow sea. <br/><br/>It also warned of an immediate attack if the South's navy violated the disputed Yellow sea borderline, and that it would consider a complete block on access to a joint industrial project in the North Korean city of Kaesong. Today's announcement came hours after 10 South Korean warships took part in an anti-submarine drill.<br/><br/>The move is in retaliation for Seoul blaming Pyongyang for a torpedo attack that sank the Cheonan in March.