SINGAPORE—Roughly 2,000 people protested against perceived inadequacies in Singapore's state-run pension system, signaling rising discontent over retirement savings in this city-state.

The demonstration Saturday was one of the largest shows of public dissent in tightly regulated Singapore, where the governing People's Action Party has seen its parliamentary dominance ebb in recent years with an increasingly vocal electorate seeking more steps to quell socioeconomic pressures.

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