Shiri (1999)

What it's about

North Korea's 8th Special Forces hijack a shipment of CTX, a potent new liquid explosive, and threatens South Korea as part of a plot to re-unify the two countries. Ryu and Lee, special agents of O.P., South Korea's secret intelligence service, attempt to track down the terrorists and find the CTX. Meanwhile Hee, the 8th's ultra-bad female sniper, resurfaces to wreak havoc and haunt Ryu.