SEOUL (Reuters) - South Korea will impose stricter social distancing rules for the greater Seoul area a month after easing them, officials said on Tuesday, warning of an even bigger crisis if anti-COVID-19 efforts fail to dampen a spike in new cases.Starting Tuesday midnight, tighter curbs will ban public gatherings of 100 people or more, limit religious services and audiences at sporting events to 30% capacity, and require high-risk facilities including clubs and karaoke bars to broaden distance among guests. South Korea has been one of the world’s coronavirus mitigation success stories after tackling the first major COVID-19 epidemic outside China with aggressive tracing and testing, but continues to battle persistent rises in infections. The tougher restrictions came as the daily case tally hovered above 200 for a fourth consecutive day, with a series of cluster outbreaks emerging from offices, medical facilities and small gatherings in Seoul and surrounding regions where around half of the country’s 52 million population live.