Mainland Chinese and Hong Kong stocks ended lower on Tuesday as sentiment was weighed down by fresh signs of Middle East tensions after US President Donald Trump urged Iranians to evacuate Tehran.

In Hong Kong, the benchmark Hang Seng Index ended down 80.69 points, or 0.34 percent, to close at 23,980.30.

The Hang Seng China Enterprises Index fell 0.4 percent to end at 8,694.67 while the Hang Seng Tech Index fell 0.15 percent to end at 5,291.85.

On the mainland, the benchmark Shanghai Composite Index closed down 0.04 percent at 3,387.40 while the Shenzhen Component Index closed 0.12 percent lower at 10,151.43.

The ChiNext Index, tracking China's Nasdaq-style board of growth enterprises, lost 0.36 percent to close at 2,049.94.

The retreat came as Israel and Iran attacked each other for a fifth straight day.

Trump left the Group of Seven summit in Canada a day early due to the situation in the Middle East, the White House said on Monday, prompting broad risk-off sentiment in global financial markets.

"One thing that is clear is that the situation continues to be highly uncertain and risks of escalation should not be ignored," analysts at Maybank said in a note.

"Safe havens should continue to be better bid and the US dollar should be better supported."

Oil and gas shares were an outperformer, as the geopolitical tensions drove crude prices higher.

A sub-index tracking the sector gained 0.92 percent.

Apart from the Middle East tensions, the focus was also on the annual Lujiazui Forum this week, traders and analysts said.

"The Lujiazui forum is likely to be the key window for financial and yuan internationalization-related policies, while the July Politburo economic meeting is likely to provide further guidance on the monetary and fiscal stance for H2 this year," said Ju Wang, head of Greater China FX and rates strategy at BNP Paribas. (Reuters/Xinhua)