A total of 12 fighters of the Shiite Houthi group were killed in airstrikes conducted by Saudi-led warplanes near the country's southeastern region of Shabwa on Friday, a military official told Xinhua."Fighter jets of the Saudi-led coalition carried out airstrikes and bombed a convoy of reinforcements for the pro-Houthi forces in a road between al-Bayda and southeastern Shabwa province," the local military official said on condition of anonymity.A number of military vehicles were completely destroyed by the airstrikes in addition to the killing of 12 Houthi fighters in the area, the source said.According to the Yemeni official, the Iranian-backed Houthi rebels sent reinforcements in an attempt to stop the continuous advancement of the Saudi-backed Yemeni government forces in the country's southeastern part.The Houthis lost control over key areas including the Bayhan district of oil-producing Shabwa province during an all-out campaign launched by Saudi-backed troops earlier this week.The Saudi-led military coalition has intensified military air campaign against Houthi positions in and around Houthis-held capital Sanaa and other northern provinces since Houthis killed former President Ali Abdullah Saleh on December 4.The coalition has intervened in the Yemeni conflict in March 2015 to roll back Iranian-aligned Houthi rebels, and backed internationally recognized President Abd-Rabbu Mansour Hadi Houthis forced into exile in Saudi Arabia.The war has killed more than 10,000 Yemenis, mostly children, displaced 3 million, and triggered the world's most humanitarian catastrophe.Tensions have escalated in Sanaa and other northern provinces after Houthis killed their top ally strongman Saleh after he changed alliance and backed the anti-Houthi coalition.