Video report by ITV News Correspondent Emma Murphy
Video footage reveals the aftermath of a missile-and-drone attack on a Saudi Arabia oil field six days ago.
Journalists, including ITV News Correspondent Emma Murphy, were given access to the Khurais oil field in Saudi Arabia's Eastern Province on Friday.
Iran has denied any involvement in the attack.
The denial came hours after America’s top diplomat alleged Tehran was behind the “unprecedented attack on the world’s energy supply” - though he offered no evidence.
ITV News Correspondent Emma Murphy gives her account of visiting the oil field
She said: "At 3.31 on Saturday morning the first cruise missile hit the Khurais oilfield.
"Over the next 17 minutes three more hit. 160 kms from the nearest city, parts of this vast site burned for hours.
"Today journalists were given access to the site for the first time. We saw the charred and bent oil stabilisation towers which took direct hits.
"On the ground huge pipes lay punctured and dented. Shrapnel, missed in the clean up, littered the ground.
"These were direct hits on an oilfield which produces a million barrels of crude oil a day.
"Little wonder then that Saudi officials are desperate to get production back to pre-attack levels. They are certainly going all out to achieve that by the end of the month. The stabilisation towers now so busy with workers they resemble bees on a hive.
"These attacks are a blow to production and a blow to pride. This is the Saudi income stream - Iran whether directly or via a proxy - has struck at the Kingdom’s heart."
The attacks, claimed by Yemen’s Houthi rebels, resulted in “the temporary suspension of production operations” at the Abqaiq processing facility and the Khurais oil field, Riyadh said.
That led to the interruption of an estimated 5.7 million barrels in crude supplies, authorities said while pledging the kingdom’s stockpiles would make up the difference.
Iran's foreign minister warned any attack on his country over the drone and missile strikes would result in "all-out war," further pushing up tensions across the Persian Gulf.
Mohammad Javad Zarif's comments on Thursday represent the starkest warning offered yet by Iran in a long summer of attacks following the collapse of Iran's nuclear deal with world powers.
His comments also appeared to be in response to U.S. Secretary of State Mike Pompeo, who a day earlier while travelling to Saudi Arabia referred to the attack as an "act of war."
Asked by CNN what would be the consequence of a U.S. or Saudi strike, Zarif said: "All-out war."
Emma Murphy speaks from Riyadh, Saudi Arabia's capital, on Thursday