SANTIAGO, April 22 (Reuters) - A strong quake was felt in the Chilean capital, Santiago, on Sunday, although there were no immediate reports of damage. The quake at 6:23 a.m. (1023 GMT) followed a strong temblor in the country's south on Saturday that caused power cuts, landslides and large waves off the nation's Pacific coast, authorities said. The length of Chile is prone to earthquakes.