Police in Nepal have clashed with pro-democracy protesters in the capital, Katmandu, firing water cannons to break up a rally and arresting at least 20 people.

Witnesses say scores of riot police with bamboo canes and plastic shields stopped activists who chanted pro-democracy and anti-monarchy slogans. The witnesses say some protesters were dragged into police vans and driven to a detention center.

The rally was organized by a coalition of human rights groups despite a government ban on protests.

The activists were protesting King Gyanendra's seizure of power in February, which he justified as necessary to crush a deadly Maoist revolt and reduce official corruption.

Some information for this report provided by AP and Reuters.