HONG KONG, Sept 30 (Reuters) - Hong Kong's benchmark index fell to a three-month low on Tuesday, finishing on its biggest monthly fall since May 2012 as investors dumped shares amid the city's worst civil unrest in decades.
Investor apprehension at how Beijing might respond next has deepened as tens of thousands of pro-democracy protesters blocked streets in Hong Kong's busiest areas, in one of the biggest political challenges to Beijing since the Tiananmen Square crackdown 25 years ago.
The Hang Seng Index lost 1.3 percent at 22,932.98 points. Having had only five winning sessions out of 21 trading days in September, the index plunged 7.3 percent this month. Tuesday's losses also pulled it into negative territory on the quarter, down 1.1 percent.
The China Enterprises Index of the leading offshore Chinese listings in Hong Kong was off 1.2 percent on the day and 0.2 percent this quarter.
Banks and property developers were the key losers. HSBC Holdings shed 1.4 percent, as did Cheung Kong Holdings .
Hong Kong markets will be closed on Wednesday and Thursday for public holidays.
Reporting by Grace Li; Editing by Eric Meijer