DUBAI (Reuters) - The Saudi-led coalition fighting the Houthi group in Yemen said it intercepted six explosive drones fired towards the kingdom on Friday, with the Houthis claiming to have launched attacks into southern Saudi Arabia since dawn. Parts of the destroyed drones fell and injured a 10-year-old boy and also a man who was driving near the Saudi city of Khamis Mushait, Saudi civil defence said. The Iran-aligned Houthis have stepped up cross-border drone and missile attacks on Saudi cities recently, mostly targeting the southern part of the country. The coalition says it intercepts most attacks. The Houthis fired the six intercepted drones towards Khamis Mushait near the Yemen border in attacks since dawn, the coalition said in statements carried by Saudi state news agency SPA and Ekhbariya TV. Houthi military spokesman Yahya Sarea said in Twitter posts on Friday that three drones had been fired at dawn, and five in the afternoon. They hit Abha International Airport and King Khalid Air Base, in the Khamis Mushait area, he said. Yemen’s Houthi forces said on Thursday they fired a missile and hit a Saudi Aramco facility in the Red Sea city of Jeddah. There has been no confirmation from the Saudi authorities. The United States and United Nations have renewed peace efforts as fighting has also intensified in Yemen’s gas-rich Marib region. On Tuesday, the U.S. Treasury Department imposed new sanctions on two Houthi military leaders. The conflict is widely seen as a proxy war between Saudi Arabia and Iran. The Houthis deny being puppets of Tehran and say they are fighting a corrupt system.