COLOMBO, Sri Lanka (AP) -- Sri Lanka's opposition and rights activists are demanding that the government punish those responsible for military's fatal shooting of three civilians during a recent protest demanding clean drinking water.

About 1,000 demonstrators including opposition lawmakers, rights activists, journalists protested outside the country's main railroad station in the capital Colombo on Wednesday. They condemned the killing of three civilians and an attack on people seeking protection in a church during another protest two weeks ago in the town of Weliweriya, northeast of Colombo.

The Weliweriya protesters were accusing a factory in their neighborhood of discharging chemical waste into drinking water.

Opposition lawmaker Mangala Samaraweera called Wednesday's demonstration the "first step of a series of protest against the state terrorism."