The ballistic missiles that North Korea test-fired this weekend could be capable of striking key government and military facilities in South Korea, a defence official said on Sunday, amid growing concerns over Pyongyang’s firepower.

North Korea fired seven ballistic missiles into the sea off its east coast on Saturday. The launches, which came on the US Independence day, were the North’s biggest one-day barrage since it fired a long-range Taepodong-2 and six smaller missiles in 2006.