A refinery in Saudi Arabia's capital Riyadh is operating normally and oil supplies have not been affected by a drone attack that took place on Thursday morning, state news agency SPA said. An attack at 4.40am, local time, in the capital caused a small fire that was controlled and did not result in any injuries or casualties, SPA <a href="https://www.spa.gov.sa/viewfullstory.php?lang=ar&newsid=2336511#2336511" target="_blank">reported</a>, citing an energy ministry official. It did not indicate where the attack originated and no one has claimed responsibility as of yet. “The refinery's operations ... the supplies of petroleum and its derivatives were unaffected,” the energy ministry spokesman said. <a href="https://www.thenationalnews.com/tags/saudi-arabia/" target="_blank">Saudi Arabia</a>, Opec's largest oil producer and the world's biggest crude exporter, has previously come under projectile and drone attacks by Yemen's Iran-aligned <a href="https://www.thenationalnews.com/gulf-news/2022/01/18/who-are-yemens-houthis-and-what-do-they-want/" target="_blank">Houthi group</a>. The attacks have been focused on oil installations, including the pipelines and storage units of <a href="https://www.thenationalnews.com/business/2021/10/31/aramco-profit-surges-on-higher-oil-prices/" target="_blank">Saudi Aramco</a>, the world's biggest corporate oil producer. The Saudi Tadawul stock market is closed for trading on Friday because of the weekend in the kingdom. Saudi Aramco's shares are up about 16 per cent since the start of the year. The company had a market value of nearly $2.2 trillion at the close of trading on Thursday. “The kingdom strongly condemns this cowardly attack ... such acts of sabotage and terrorism, repeatedly committed against vital installations and civilian facilities, do not target the kingdom alone, but more broadly the security and stability of energy supply to the world and, thus, negatively affecting the global economy,” the spokesman said. Brent, the global benchmark for two thirds of the world's oil, was trading 0.36 per cent lower at $109.10 a barrel at 7.24am UAE time on Friday while West Texas Intermediate, the gauge that tracks US crude, was 0.19 per cent higher at $106.20 a barrel.