The Hang Seng Index fell 0.8 per cent to 26,488.53 as of 10.11am local time. The Hang Seng Tech Index dropped 1.5 per cent. On the mainland, the CSI 300 Index climbed 0.1 per cent and the Shanghai Composite Index added 0.2 per cent.
Alibaba Group Holding fell 3 per cent to HK$146.30 and Tencent Holdings lost 1.5 per cent to HK$623. Electric-vehicle maker BYD lost 2.6 per cent to HK$96.60 and PetroChina declined 2.1 per cent to HK$8.09.
In the latest flare-up between the two Asian neighbours, China said on Tuesday that it would immediately ban exports of products to Japan with potential military use. Beijing was also mulling tightening export reviews for some rare earth-related items, the state-run China Daily reported.
Elsewhere in Asia-Pacific, most markets rose with the exception of Japan, where the Nikkei 225 fell 0.3 per cent. South Korea’s Kospi rose 0.7 per cent and Australia’s S&P/ASX 200 added 0.2 per cent.
