TOKYO: Japan's Nikkei share average fell on Thursday, weighed by a sell-off in chip-related stocks, while escalating US-Iran tensions reignited inflation concerns and prompted investors to shun risky assets.

The Nikkei was down 1.30 per cent at 63,360.96 as of 0046 GMT. Earlier in the session, the benchmark fell by as much as nearly three per cent, slipping below the 63,000 level for the first time since May 22.

The broader Topix slid 1.60 per cent to 3,787.08.

Washington carried out renewed strikes against multiple targets overnight in Iran, the US military said on Wednesday, hours after President Donald Trump vowed new attacks if no peace deal is secured.

Tech investment conglomerate SoftBank Group dragged the Nikkei index lower, falling 3.60 per cent.

Fujikura Ltd, which produces optical fibre that is a key component of AI data centres, lost six per cent, while semiconductor testing equipment maker Advantest Corporation shed 3.70 per cent.

There were 184 decliners in the Nikkei index against 40 advancers.