Saudi Arabia’s oil production has dropped by more than half due to drone strikes at two plants in the center of Saudi Arabia’s oil industry.

Yemeni Houthi rebels say they attacked the two plants early Saturday morning. Fears that oil prices will rise and tensions in the Middle East will intensify as a result, news agency Reuters reported.

According to the Saudi state-owned oil company Saudi Aramco’s statement, the attack will reduce the country’s daily oil production by 57 million barrels.

It accounts for more than five percent of the world’s total oil supply, Reuters reported.

 Houthis launched missile and drone attacks on Saudi oil industry several times before the attack, but this is the most brutal attack so far; It will temporarily cripple more than half of the country’s oil production capacity.

Saudi Arabia is the world’s largest oil exporter. Every day the country exports more than 11 million barrels of oil.

 While the Houthis claimed responsibility for the attack, US Secretary of State Mike Pompeo also blamed Iran for the attack. “There is no evidence that the attack was from Yemen,” he claimed in a tweet. 

“Despite all the calls for a reduction in tensions, Iran has now launched an unprecedented attack on world energy supplies,” Pompeo said.

Saudi Riyadh has told US President Donald Trump over the telephone that Riyadh has the ability to “deal with and fight this terrorist attack,” according to Saudi state news agency SPA.

The United States condemns the attack and says Trump is ready to work with Riyadh to ensure Saudi Arabia’s security.

The US Department of Energy has said they are ready to release oil from strategic petroleum reserves if needed. US Ministry of Energy Rick Perry has said his ministry will work with the International Energy Agency if it is necessary to take international action in the midst of turmoil.

 Saudi-led Sunni coalition forces intervened in the country’s civil war in 2015 after Iranian-backed Yemeni Shiite rebels occupied most of the country, including the capital Suna. Ever since the Saudi coalition launched a massive airstrike in Yemen, the Houthis have occasionally responded to throwing missiles at Saudi territory. But recently they started using missiles as well as drones to attack Saudi.

 Over the past few months, the Houthis have carried out drone and missile attacks in different cities and establishments in Saudi Arabia. 

Saudi Arabia blames Iran’s regional rival Iran for the attacks, while Tehran denies the allegations. Riyadh, on the other hand, has denied allegations that Iran is supplying arms to the Houthis, while both the Houthis and Tehran have denied the allegations.

 Saudi Arabia spokesman Turkey al-Maliki said an investigation had been launched into who had planned the attack and who was implementing it. The Western-backed coalition will prevent threats to global energy security and economic stability, he said. Aramco chief executive Amin Nasser said no one was hurt in the attack. 

 Saudi Arabia’s Minister of Energy Prince Abdulaziz bin Salman has said Aramco will get more information within 48 hours.