CAIRO/TEHRAN, Sept. 16 (Xinhua) -- The recent attacks on Saudi Arabia's Aramco oil facilities have escalated the tensions in the Gulf, as Iran and the United States trade barbs and threats of military retaliation.

The attacks, which have halved the Saudi oil output, sent shock waves through the global oil market by triggering a price hike and fueling new fears about the declining global economy already clouded by the uncertainties caused by the trade war ignited by the irresponsible policies of the United States.

There are calls for restraint and return to talks by the concerned parties in this volatile region as any miscalculation could spark an armed conflict whose consequences on the Middle East and the whole world could be disastrous.

NEGATIVE IMPACT ON GLOBAL OIL SUPPLY

Saudi Arabia announced on Saturday that drone attacks caused fires at two Aramco oil facilities, including the Abqaiq processing plant and Khurais oil field, in the east of the Kingdom, the top oil exporter in the world.

The explosions knocked out crude oil supplies estimated at 5.7 million barrels per day, or about 50 percent of the company's production, which accounts for nearly 6 percent of daily global consumption of crude oil.

News about the attacks on Aramco, the state-run Saudi oil giant, sent global oil price hiking by as high as 18 percent on Sunday, before falling back to a 12 percent rise.

On Monday morning, U.S. oil futures rose to 60 U.S. dollars a barrel, while the futures of Brent crude climbed to 66 dollars per barrel, both up by 12 percent.

U.S. President Donald Trump tweeted on Sunday that he approved the release of oil from the U.S. strategic reserve, if needed, to keep the global oil market "well-supplied."

The rise in oil prices have deepened the fears about the global economic downturn.

Hany Soliman, executive manager of Arab Center for Researches and Studies in Cairo, Egypt, told Xinhua that the oil price spike could threaten the world oil supply and the people's life.

"So, Iran wants to turn the problem from local or regional to international crisis," he said, citing Iran is somewhat related to the attacks as the Houthis are allied with Tehran.

BLAME GAME ON WHO IS BEHIND ATTACKS

In the wake of the attacks, the U.S. and Iran started a blame game on who should be held responsible, with both sides pointing the finger at each other for heightening the tensions in the Middle East.

Earlier on Saturday, Yemen's Iran-allied Houthi rebels claimed responsibility for launching a 10-drone attacks on major oil facilities in Saudi Arabia as a retaliation against "the Saudi regime's aggression and economic blockade" against Yemen.

However, the U.S. squarely held Iran accountable for the attacks, insisting that they did not come from Yemen as the Houthis claimed.

"Amid all the calls for de-escalation, Iran has now launched an unprecedented attack on the word's energy supply. There is no evidence the attacks came from Yemen," U.S. Secretary of State Mike Pompeo tweeted on Saturday.

Other U.S. officials said that investigations showed that the points of impact were located mainly in the northwestern side of the Aramco facilities, indicating that the attacks came from Iran or Iraq, which are located to the north of the Kingdom, instead of Yemen, which is located to the south.

But Iran strongly dismissed the U.S. accusations as "baseless" "big lies."

Iranian Foreign Ministry's spokesman Abbas Mousavi said in a statement on Sunday that the U.S. accusations are "meaningless and incomprehensible within the diplomatic norms."

Mousavi said on Monday that the Houthi attacks on Saudi targets was a natural response from the Yemenis and their army to the "crimes" committed by the Saudi-led coalition in Yemen.

Iran's President Hassan Rouhani on Sunday described the U.S. policies as the "root cause of problems in the Middle East region."

"What is taking place in this region ... is the result of erroneous plans and conspiracies of the United States," Rouhani said before leaving for Ankara, Turkey to hold a trilateral summit with leaders of Russia and Turkey.

RISKS OF U.S.-IRAN OR SAUDI-IRAN CONFLICT

The attacks on Saudi oil facilities have ratcheted up the already tense situation in the Middle East caused by the U.S. maximum pressure policies on Iran, including a total oil trade ban.

On Monday, the Saudi-led coalition said that initial investigations indicated that Iranian weapons were used in the two Saudi Aramco attacks, while refraining from directly blaming them on Iran.

There are fears that the rising tensions could spark a military conflict in the Gulf between Iran and the U.S. or Saudi Arabia, as Trump has issued a warning to Iran.

"There is reason to believe that we know the culprit, are locked an loaded depending on verification, but are waiting to hear from the Kingdom as to who they believe was the cause of this attack, and under what terms we would proceed!" Trump said in a tweet.

Iran remains defiant in face of the U.S. threat, while the Saudis took a cautious stand by avoiding blaming any party for the attacks pending an investigation.

A top commander of Iran's Islamic Revolution Guards Corps (IRGC) warned on Sunday that the U.S. military bases in the region are within reach of Iranian missiles.

If a conflict is ignited, the U.S. warships will be the first to be targeted by Iranian missiles, Amir Ali Hajizadeh, commander of the IRGC's Aerospace Division said.

However, experts said the likelihood of a full-out war between Iran and Saudi Arabia, the two traditional rivals in the region, or between Iran and the U.S. is limited as it could result in uncontrollable consequences on regional or international stability.

Trump called off a strike on Iran in June, which he ordered initially to retaliate against Iran's shooting down a U.S. drone in the Gulf. It is believed that Trump, who quitted the 2015 Iranian nuclear deal last year and has restored suffocating sanctions on Tehran, is uninterested in going to a war at a time when he is heading toward reelection in 2020.

DIALOGUE URGED TO PREVENT FURTHER ESCALATION

The international committee has expressed worries about the rising tensions in the Gulf following the attacks on Saudi oil supply, while calling for restraint and dialogue to resolve the crisis.

UN Secretary-General Antonio Guterres on Sunday condemned the attacks on Saudi oil facilities, while urging "all parties to exercise maximum restraint, prevent any escalation amid heightened tensions."

Experts said that whether the Aramco attacks are done by the Houthi rebels or Iran, it is related to the U.S. sanctions imposed on Tehran, which is forced to take counter measures in a bid to force Washington to back down.

"The Iranian-Saudi deteriorated ties cast negative shadow on the Gulf region and on the world generally. When the conflict affects the oil prices, the world economy will be impacted," Ikram Bader, a professor of political science in Cairo University, told Xinhua in an interview.

Bader suggested the Gulf partners reach a common stand in dealing with Yemen's crisis and finish the war there "which will definitely break the icy ties between Riyadh and Tehran."

Soliman, an expert in the Iranian affairs, said that the parties concerned should ease the tensions by reaching a mechanism for negotiations and find a political solution.

"The U.S. and Iran should sit down on the negotiation table and avoid escalation. They should reach a mechanism on the nuclear deal," he said.