The Yemeni Popular Resistance forces repelled an attack by Houthi rebels in the city of Aden, a leader of the resistance told the German Press Agency (DPA) Saturday. The source, who asked to remain anonymous, said that violent clashes erupted between the Houthis and the Popular Resistance in Saladin, adding that the Houthi fighters had used heavy weaponry and tanks during the battle. The Houthis withdrew after sustaining heavy losses, however the Popular Resistance forces remain on high alert, as the Shiite fighters are expected to launch another attack as soon as they recover from their losses, the source revealed. Yemen has witnessed massive clashes between Houthis and the national forces in the last few years causing instability and chaos across the country. The Houthis participated in the 2011 Yemeni demonstrations that ousted Yemeni President Ali Abdullah Saleh. They took part in the National Dialogue Conference in February 2014, which called for dividing Yemen into a federation of six regions.