PYONGYANG, April 20 (Xinhua) -- Kim Jong Un, general secretary of the Workers' Party of Korea and president of the State Affairs of the Democratic People's Republic of Korea (DPRK), on Sunday supervised a test-fire of the improved surface-to-surface tactical ballistic missile Hwasongpho-11 Ra, the official Korean Central News Agency (KCNA) reported Monday.

The purpose of the test-fire is to verify the characteristics and power of cluster bomb warhead and fragmentation mine warhead applied to the tactical ballistic missile, according to the KCNA.

Five tactical ballistic missiles, launched toward the target area around an island about 136 km away, struck the area of 12.5-13 hectares with the very high density, fully displaying their combat might, the report said.

Expressing his satisfaction over the test results, the DPRK leader said the development and introduction of different cluster bomb warheads can meet the operational demand of the country's armed forces in a more satisfactory and effective way, said the report.