Seven people were killed when landslides struck Indonesia's North Sumatra province, a disaster management official said on Sunday.Heavy downpours triggered soils of a 100-metre high hill to slide down in Sukamaju village of Gomo sub-district, reports Xinhua news agency.The landslides on Saturday night hit a house where the seven villagers were staying, the official said.To avoid further risks of landslides, authorities have evacuated all those living in the slope of the hill.