South Korean naval special forces rescued 21 sailors and their cargo ship hijacked last week in the Arabian Sea by Somali pirates, Seoul's Joint Chiefs of Staff (JCS) said Friday.

The unprecedented rescue operation, initiated early Friday morning in the Arabian Sea, left eight Somali pirates dead and five captivated.

"The operation demonstrated the government's strong resolution that we will never make concessions about illegal activities by pirates," Lee Sung-ho at the JCS told reporters in a briefing. The South Korean captain has sustained a gun wound but he is not in a critical condition, he added.

The 11,500-ton Samho Jewelry was sailing from the United Arab Emirates to Sri Lanka when hijacked last Saturday. Twenty-one crew members, including eight South Koreans, two Indonesians and 11 others from Myanmar, were aboard the South Korean-owned cargo vessel.

"(South Korea) will never tolerate any act that threatens life and safety of South Korean nationals," President Lee Myung-bak said in a statement.