In the video, it can be seen that Saudi bunkers are being assaulted by Houthis rebels. At the end of the video, you can hear their usual chant “death to America, death to Israel..”
The Houthi insurgency in Yemen was a sectarian military rebellion pitting Zaidi Shia Houthis(though the movement also includes Sunnis) against the Yemeni military that began in Northern Yemen and has since escalated into a full-scale civil war.
It began in June 2004, when dissident cleric Hussein Badreddin al-Houthi, a leader of the Zaidi sect, launched an uprising against the Yemeni government. Initially, most of the fighting took place in Sa’dah Governorate in northwestern Yemen, but some of the fighting spread to neighbouring governorates Hajjah, ‘Amran, al-Jawf and the Saudi province of Jizan. Since 2014 the nature of the insurgency has changed with the Houthi takeover in Yemen and then into the ongoing Civil War with a major Saudi-led intervention in Yemen beginning in 2015.
According to a February 2015 Newsweek report, Houthis are fighting “for things that all Yemenis crave: government accountability, the end to corruption, regular utilities, fair fuel prices, job opportunities for ordinary Yemenis and the end of Western influence.