India, June 12 -- Hong Kong stocks tumbled and the currency soared as interbank interest rates jumped amid protests that closed roads in the city's financial district.

The Hang Seng Index was 1.6% lower as of the midday break, with local property developers among the biggest losers, while the Hong Kong dollar strengthened as much as much as 0.15%, the biggest gain in six months. The one-month interbank borrowing cost, known as Hibor, rose 29 basis points to about 2.42%, the highest since 2008.

While some analysts attributed the tighter liquidity to seasonal demand for cash such as dividend payments, others said the protests -- aimed at preventing the passing of a bill allowing Hong Kong to extradite its citizens to mainland China -- cou...