HONG KONG, June 16 (Reuters) - Hong Kong stocks fell to their lowest in 10 weeks on Tuesday, with investor risk appetite curbed by political uncertainty ahead of this week's vote on electoral reform, Greek debt default worries and slumping mainland shares.
The Hang Seng index fell 1.1 percent, to 26,566.70, its lowest closing level since early April. The China Enterprises Index lost 2.7 percent, to 13,252.93 points.
Chinese shares posted their biggest fall in nearly three weeks on Tuesday on fears over margin tightening and new share supplies.
Investors are also cautious as the former British colony is bracing for a fresh democracy showdown this week as a crucial vote on a China-backed electoral reform package will be held.
Dozens of police stood guard around Hong Kong government headquarters on Tuesday, a day after authorities arrested 10 people and seized suspected explosives.
Nearly all sectors, including energy, property and construction, and financials fell. (Reporting by Samuel Shen and Pete Sweeney; Editing by Jacqueline Wong)