Washington CNN  — 

Secretary of State Mike Pompeo pinned the blame on Iran for an attack at a Saudi oil field in a pair of tweets Saturday.

Drone strikes on crucial Saudi Arabian oil facilities have disrupted about half of the kingdom’s oil capacity, or 5% of the daily global oil supply, CNN Business reported earlier Saturday. Yemen’s Houthi rebels took responsibility for the attacks but they are often backed by Iran.

But preliminary indications are that the attacks did not originate from Yemen and likely originated from Iraq, according to a source with knowledge of the incident. The same official said the damage was caused by an armed drone attack.

CNN National Security Analyst Peter Bergen said there have been more than 200 drone and missile attacks launched by Houthi rebels from Yemen into Saudi Arabia, and none have been as effective as Saturday’s attack, lending credence to the belief that the attack did not originate from Yemen.

“Tehran is behind nearly 100 attacks on Saudi Arabia while Rouhani and Zarif pretend to engage in diplomacy,” Pompeo tweeted, referencing Iran’s president Hassan Rouhani and foreign minister Mohammad Javad Zarif.

“Amid all the calls for de-escalation, Iran has now launched an unprecedented attack on the world’s energy supply. There is no evidence the attacks came from Yemen,” Pompeo continued, providing no evidence that Iran was behind the attacks.

Iranian foreign ministry spokesman, Seyyed Abbas Mousavi, rejected the accusation that Iran was behind the attack.

“Such blind accusations and inappropriate comments in a diplomatic context are incomprehensible and meaningless,” he said, adding: “even hostility needs a certain degree of credibility and reasonable frameworks, US officials have also violated these basic principles.”

Saudi Arabia has been leading a military campaign to quash the Houthi rebels in Yemen since March 2015. The conflict is widely seen as a proxy war between the Saudis and Iran, which has been backing the Houthis.

Pompeo also called for other countries to denounce Iran and promised American efforts to help support the energy market.

“We call on all nations to publicly and unequivocally condemn Iran’s attacks,” he tweeted. “The United States will work with our partners and allies to ensure that energy markets remain well supplied and Iran is held accountable for its aggression.”

According to the Wall Street Journal, officials are investigating the possibility that the attacks involved cruise missiles.

CNN has independently reached out to the State Department for further information regarding the attack and who was involved.

Lawmakers on both sides of the aisle weighed in on Pompeo’s characterizations of the attack.

“This is such irresponsible simplification and it’s how we get into dumb wars of choice,” Democratic Sen. Chris Murphy of Connecticut tweeted in response to Pompeo.

“The Saudis and Houthis are at war,” he added. “The Saudis attack the Houthis and the Houthis attack back. Iran is backing the Houthis and has been a bad actor, but it’s just not as simple as Houthis=Iran.”

Meanwhile, Republican Sen. Tom Cotton of Arkansas vowed that “the United States stands with our Saudi partners in confronting Iran’s campaign of terror across the Middle East.”

“The ayatollahs’ desperate efforts to cripple global energy markets will only renew our commitment to maximum pressure, he added in a statement. “The Iranian regime and its proxies ought to face consequences for these attacks.”

President Donald Trump called Saudi Crown Prince Mohammad bin Salman on Saturday to offer his support for the country’s self-defense, White House deputy press secretary Judd Deere said in a statement.

“The United States strongly condemns today’s attack on critical energy infrastructure,” Deere said. “Violent actions against civilian areas and infrastructure vital to the global economy only deepen conflict and mistrust.”

The US government “remains committed to ensuring global oil markets are stable and well supplied,” the spokesman said.

Energy Secretary Rick Perry “stands ready to deploy resources from the Strategic Petroleum Oil Reserves if necessary to offset any disruptions to oil markets” as a result of the attack on Saudi oil facilities, Department of Energy spokesperson Shaylyn Hynes said in a statement.

Perry was briefed on the attacks and directed agency leadership “to work with the International Energy Agency on potential available options for collective global action if needed,” Hynes added.

A Department of Energy official also noted that the US Strategic Petroleum Oil Reserves “holds 630 million barrels…for exactly this purpose.”

CNN’s Sara Mazloumsaki, Jeremy Diamond, Gregory Clary, John Defterios, Victoria Cavaliere, Nada Altaher, Jennifer Hauser, Ivana Kottasová and Jamie Ehrlich contributed to this report.