TOKYO, July 16 (Reuters) - Japan’s benchmark Nikkei share average fell below the psychologically key 28,000 mark on Friday as tech shares tracked declines on Wall Street overnight, while a continued surge in coronavirus infections dented investor sentiment. New COVID-19 infections leapt to 1,308 cases in Tokyo on Thursday, the highest since January, a week before the city hosts the Olympics, which could potentially spark a renewed surge in infections amid the influx of foreign athletes and officials. “New cases have already surpassed the peak of the fourth wave in May, and we could see the number rising above the January peak,” said Norihiro Fujito, chief investment strategist at Mitsubishi UFJ Morgan Stanley Securities. “It is hard to expect the surge in infections to subside any time soon, which obviously delays Japan’s economic recovery. That is what markets are pricing in now.” The tech-heavy Nikkei sank as low as 27,847.35 before ending the morning session down 1.1% at 27,974.72, after the Nasdaq Composite led declines in U.S. shares with a 0.7% drop. Among components, chipmakers Advantest and Tokyo Electron lost 3% and 2.2%, respectively, after rival TSMC signalled plans to build new factories in the United States and Japan, and expand production capacity in China. Camera-manufacturers Nikon Corp and Olympus fell 2% and 1.8%, respectively, while Sony Group Corp sank 2%. The Nikkei’s biggest decliner was Eisai, which fell 9.7% after some large hospitals declined to use an Alzheimer’s drug similar to the one it developed with Biogen. Uniqlo clothing brand-owner Fast Retailing fell 3.8% after trimming its full-year profit forecast. The broader Topix was down 0.3% to 1,934.53. The drag from tech shares was clear with the Topix Growth Index sliding 0.5% while the Value Index was flat. Sony was the biggest decliner among the core 30 Topix names. Nintendo, not included in the Nikkei, was also among the worst performer, down 1.4%. SoftBank Group slipped 0.8%. Among Topix sectors, miners were the biggest decliners for the second day, down 1.5% as crude oil prices continued to drop. Eisai dragged pharmaceuticals down 1.4%, while precision machinery makers dropped 1.2%. (Reporting by Kevin Buckland in Tokyo, Additional reporting by Hideyuki Sano; editing by Vinay Dwivedi)