After much speculation over his whereabouts, it appears North Korea's number two in command has returned to Pyongyang after surgery overseas.

A source on North Korean affairs said Wednesday that Hwang Pyong-so, the director of the North Korean military's General Political Bureau, recently went abroad for back surgery and is believed to have returned to the North.

The source said it is common for high-ranking North Korean officials to have back problems because they're required to stand rigidly for long periods at political events. 

Hwang has not appeared in public for about 20 days, during which he missed eight on-site inspections by North Korean leader Kim Jong-un. 
 
Hwang last appeared in public on November 11, when he spoke at the funeral service for former key military official, Ri Ul-sol.