The accident took place on Sunday night in North Hwanghae province, when the tour bus plunged off a bridge, reports the BBC.
It is rare for North Korea's tightly-controlled media to report on negative news, and for Kim to acknowledge the incident itself is even more unusual.
China is the North's main political ally and largest trading partner.
629 said that the unexpected accident brought bitter sorrow to his heart
70He couldn't control his grief at the thought of the bereaved families who lost their blood relatives.""