SHANGHAI: Hong Kong's main stock indexes touched their lowest since mid-2013 on Thursday, as panic from China's 7 percent market free-fall spilled over the border.

The Hang Seng index dropped as much as 3.1 percent, to 20,323.97 points, the lowest intraday level since July, 2013.

The Hong Kong China Enterprises Index, which tracks mainland companies, was down as much as 4.4 percent, touching an intraday low of 8,688.28 points, the lowest level since June, 2013.

All main sectors fell, with sentiment soured by another slump in mainland equities.

China's benchmark CSI300 index slumped 7 percent after less than 30 minutes of trading, triggering the circuit breaker mechanism that halted share transactions for the day.

The tumble in China was triggered by a further weakening in the yuan, gloomy prospects for China's economy, and fears of an equity supply glut when a sales ban expires on Friday.--REUTERS