Asian stock markets traded lower on Tuesday as renewed fighting in the Middle East unsettled investors. Japan's Nikkei 225 fell 0.49%, South Korea's Kospi declined 0.42% and Australia's S&P/ASX 200 slipped 0.31%.

The weaker start followed fresh military exchanges between the US and Iran after a period of relative calm. American forces struck an island in the Strait of Hormuz, while Iran responded with attacks targeting the United Arab Emirates and Jordan.

Oil prices extended their advance in early Asian trading, with Brent crude rising above $91 a barrel as the latest escalation raised concerns about energy supplies and shipping through the key waterway.

US stock futures were little changed after Wall Street ended Monday lower, although the major benchmarks still recorded monthly gains in August. Dow Jones Industrial Average futures rose 48 points, while S&P 500 futures gained less than 0.1%. Nasdaq-100 futures were broadly unchanged.