TOKYO - Japan have been ordered to move five Pacific Nations Cup matches to Fiji in the wake of last month's deadly earthquake and tsunami and fears over the current nuclear crisis.

The Japan Rugby Football Union (JRFU) said on Tuesday only the July 2 curtain-raiser against Samoa had survived after the International Rugby Board (IRB) decided on the switch.

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"It was an extremely difficult decision to take but it is one we must accept," JRFU General Secretary Tatsuzo Yabe told reporters. "We had put in so much work to organise a wonderful tournament. It's a great pity."

Apart from Japan's opener against Samoa in Tokyo, the remainder of the competition from July 9-13 will be held in Fiji, which hosted the 2009 Pacific Nations Cup.

Sporting events have been thrown into chaos following the 9.0 magnitude earthquake and devastating tsunami on March 11, which left 28,000 dead or missing in northeast Japan.

The huge tsunami wave triggered by the quake severely damaged a nuclear plant in Fukushima some 240 km (150 miles) north of Tokyo.

Workers have been battling around the clock to prevent further radiation leaks and prevent a Chernobyl-like meltdown, forcing the abandonment of major sports events across Japan.

Professional baseball and soccer, Japan's two biggest spectator sports, were forced to postpone the start of their seasons.

The world figure skating championships and a world championship series triathlon race were other events recently affected by the disaster.