Hong Kong: Asian stock markets mostly declined on Thursday, led by a sharp sell-off in South Korea, while oil prices edged lower despite continued military tensions between the United States and Iran.South Korea's Kospi index plunged 6.6 percent to 6,816.70, marking the steepest decline among major regional markets. The drop came after the Bank of Korea raised interest rates for the first time since 2023, citing inflationary pressures linked to the ongoing conflict involving Iran.Technology stocks were among the biggest losers. Memory chipmaker SK Hynix fell 11.2 percent, while Samsung Electronics dropped 8.2 percent.Japan's Nikkei 225 declined 2.9 percent to 66,767.64, weighed down by losses in semiconductor-related stocks. Kioxia tumbled 13.5 percent, while Tokyo Electron and Advantest fell 5.2 percent and 5.6 percent, respectively. SoftBank Group lost 6.4 percent.In Taiwan, the Taiex slipped 0.3 percent ahead of earnings results from chip giant TSMC, often viewed as a key indicator for the global semiconductor and artificial intelligence sectors.Hong Kong was the exception to the regional downturn, with the Hang Seng Index rising 1.7 percent to 25,111.22. Shares of Alibaba gained 4.4 percent after Chinese regulators approved Apple's AI service for use in China, with Alibaba's Qwen model expected to be integrated into the platform.Mainland China's Shanghai Composite Index fell 0.9 percent, while Australia's S&P/ASX 200 eased 0.2 percent. India's Sensex rose 0.3 percent.Oil prices retreated slightly but remained elevated amid concerns over shipping disruptions in the Gulf.Brent crude slipped 0.4 percent to US$84.55 a barrel, while US West Texas Intermediate crude fell 0.2 percent to US$79.34 a barrel.Analysts said tensions between Washington and Tehran continue to affect shipping activity through the Strait of Hormuz, a critical route for global oil exports.On Wall Street overnight, the S&P 500 gained 0.4 percent, the Dow Jones Industrial Average rose 0.3 percent, and the Nasdaq Composite added 0.6 percent, supported by easing US inflation data and strong corporate earnings.