NEW : At least 23 people are missing , including two on a school bus . NEW : Police are able to rescue 70 stranded people . Megi is blamed on southern China after deadly triggering incident in Taiwan .
NEW : At least 23 people are missing , including 19 on a tour bus . NEW : Helicopters are able to evacuate 70 stranded tourists . Megi is advancing on southern China after deadly triggering mudslides in Taiwan .