Seoul, July 4 (Reuters): North Korea fired seven ballistic missiles today, South Korea’s defence ministry said, in an act of defiance towards the US that further stoked regional tensions already high due to its nuclear test in May.

South Korea’s Yonhap news agency said the missiles were “Scud-type”, marking an escalation of recent sabre-rattling by the reclusive North, which has fired several non-ballistic, short-range missile since the May 25 nuclear test.

North Korea is barred by UN resolutions from firing ballistic missile such as the Scud. A South Korean defence ministry official said more launches could come soon.

It was the biggest barrage of ballistic missiles the North has fired since it launched seven missiles in 2006 around the US July 4 Independence Day holiday, including its longest-range Taepodong-2.

The launches came as the US has cracked down on firms suspected of helping the North in its trade in arms and missiles. They were subject to UN sanctions imposed after the nuclear test and are a vital source of foreign currency for the cash-short state.