Yemen's Houthi fighters expand power base

Yemen's Shia Houthi fighters are becoming a political and military force to be reckoned with. The group was originally a small limited faction based in the northern town of Saada. But now it is a huge and heavily armed rebellion taking over new territories in the south. They are strongly opposed to a proposed division of the country into six regions. Al Jazeera's Mohammed Vall reports from Sanaa.