The Houthis ascent is the latest blow to central authorities in Yemen, who have struggled to keep control since mass protests in 2011 forced the country's long-serving president, Ali Abdullah Saleh, to step down.
In a separate sign of the fragility of Yemen's embattled state, southern separatists seeking to split from the north set an ultimatum for the government to evacuate its soldiers and civil servants by November 30.
This is a core source of contention for Saudi Arabia towards Iran as seen earlier this week in the diplomatic spat made public between the two countries, with Saudi Arabia identifying Iran as a cause of Houthi military and political ascendancy currently taking effect in parts of Yemen.
Houthi appear to have integrated into or supplanted Yemen Army and police ranks in the capital city.
The deaths in Khost occurred as the Taliban stepped up a renewed assault on government forces across the country in recent days.
In the southern province of Helmand, Taliban fighters killed Muhammad Anwar, the district governor of Nad Ali district, in an ambush on his vehicle late Tuesday.
For example, in Iraq, where Shia forces that benefited greatly from our invasion ended up fighting us anyway
The Iraqi military in Anbar province is currently in disarray, the Iraqi Army has moved in units from outside of Anbar after the Islamic State rendered most of the 7th Division which is based in the province, combat ineffective.