South Korea probes Halloween crowd surge deaths as nation mourns

South Korean President Yoon Suk Yeol arrives to pay tribute to the victims (Ahn Young-joon/AP)

South Korean police are investigating what caused a crowd surge that killed more than 150 people, including 26 foreigners, during Halloween festivities in Seoul.

Meanwhile, President Yoon Suk Yeol joined tens of thousands of others to pay respects to the dead at special mourning sites.