Four cargo vessels were subjected to "sabotage operations" off the coast of Fujairah, the UAE's Foreign Ministry has said.
The incident took place on Sunday morning near UAE territorial waters in the Gulf of Oman.
It said that there had been no injuries or fatalities on board the vessels and no spill of chemicals or fuel.
The Ministry of Foreign Affairs and International Co-operation said acts of sabotage on civilian vessels and threatening the safety and lives of those on board "is a serious development".
An investigation is continuing. It did not apportion blame or identify suspects. The nature of the attack was not immediately clear and the names of the vessels and their operators are yet to be released.
But on Monday, the Saudi energy minister Khalid Al Falih confirmed two Saudi oil tankers were among those attacked, suffering "significant damage to the structures of the two vessels". He said the attack took place about 6am.
Reuters said shipping sources identified the Saudi vessels as Bahri-owned very large crude carrier tanker Amjad and crude tanker Al Marzoqah. Bahri, Saudi's national shipping carrier, has yet to comment.
Tanker industry tracking sites showed the Amjad is currently anchored several kilometres off Mirbah near Khor Fakkan and Al Marzoqah anchored off Fujairah port.
Sky News Arabia aired footage of Al Marzoqah on Monday though damage was not visible in the clip.
The two other ships have been identified as the A Michel - registered in Sharjah - and the Andrea Victory from Bergen in Norway.
On Monday, the UAE's Minister of State for Foreign Affairs Dr Anwar Gargash said on Twitter that "the deliberate sabotage of the four vessels" took place in the country's "territorial waters", which extend 22km from the coast.
Dr Abdullatif bin Rashid Al Zayani, Secretary General of the GCC, denounced the act of sabotage, describing it as "a serious escalation which demonstrates evil intents by those who planned and carried it out, undermining the safety of maritime traffic in the region and threatening the safety and lives of those on board".
Al Zayani called on the international community and international organisations concerned with maritime navigation to assume their political and legal responsibilities to prevent such acts by any parties attempting to undermine maritime traffic safety and security.
"Such irresponsible acts will increase tension and conflicts in the region and expose its peoples to great danger," he said.
Earlier, the UAE was the subject of false accounts of an attack after news outlets with links to the Kremlin, Hezbollah and Iran spread claims that a series of explosions had occurred on land at Fujairah’s port.
Reports that between seven and 10 oil tankers anchored at the port were in flames were shared widely on social media accounts on Sunday.
Some reports said that American and French warplanes had been flying over the port at the time of the incident.
The Foreign Ministry described the claims as "baseless and unfounded".
Authorities in Fujairah earlier said operations at the port were continuing as normal. News of the sabotage was announced shortly after 7pm.
The reports of fire and explosions that emerged on Sunday morning apparently originated in Al Mayadeen, a Lebanese broadcaster and news outlet regarded as pro-Hezbollah.
They were quickly picked up and reported by Sputnik news, which is funded by Russia, and spread across social media by pro-Iran Twitter accounts.
An image of a flaming tanker purporting to be evidence of the attack was a picture of a tanker called the Kashmir on fire in Jebel Ali in 2009.
Among the comments spread by pro-Tehran accounts along with the news stories were warnings that it was not safe to travel to the UAE and that air travel had been severely disrupted.
Hamad Al Rahoomi, a member of the UAE’s Federal National Council, said foreign broadcasters had exaggerated the scale of the incident and claimed that the port was on fire.
“It is weak. It was clear this was fake news," Mr Al Rahoomi said. "Everybody can see the location. Something like that you would have been able to see for miles and miles."
Bahrain strongly condemned the sabotage. In a statement by Bahrain News Agency late on Sunday, the Bahraini Foreign Ministry denounced the act, saying it was aimed at threatening the security and stability of marine navigation.
It urged the international community to guarantee the safety of marine navigation and confront all attempts to undermine international peace and security.
The governments of Jordan and Yemen also condemned the sabotage.
On Sunday, amid reaction to the false reports, senior Iranian politician Heshmatollah Falahatpisheh, head of parliament’s national security committee, claimed that the "explosions" showed that the security of Gulf states was "fragile".
Press TV, the Iranian state-funded English-language broadcaster, ran an interview with Hadi Kobaysi, who it described as a Beirut political analyst.
Mr Kobaysi claimed the incident showed there was a “problem” with how the UAE managed its critical infrastructure and speculated that there may be a link with the conflict in Yemen.
Press TV continued broadcasting the interview hours after the reports were denied by UAE authorities and in the absence and any independently verified reports to back up the claims.
Sputnik also continued to report the story prominently alongside the denials.
Quoting Al Mayadeen, Sputnik claimed “seven oil tankers were completely burnt and firefighters were still trying to extinguish the blaze".
Claiming its story was based on unidentified sources in the Gulf, Al Mayadeen later claimed to have obtained names and numbers of the tankers involved.
The misinformation comes at a tense time in the region, with Iran last week suspending compliance with parts of the 2015 nuclear deal. Last week President Hassan Rouhani said Iran was pulling out of two commitments. He said the country would keep enriched uranium stocks rather than sell its surplus abroad, as they are required to under the deal. He also said Iran would begin developing its Arak heavy water reactor.
Heavy water is a moderator used in a type of reactor that can produce plutonium.
Adding to the tension is news that the US has sent a carrier group to the region to counter what the White House claims are "clear indications" of threats from Tehran to its forces.
Fujairah is in a key location strategically, lying just outside the Strait of Hormuz. The strait is a vital oil and natural gas corridor for the global energy market and Iran has repeatedly threatened to block it.
The world’s largest crude oil storage centre is being built in Fujairah.
In response to the reports of explosions yesterday afternoon, Fujairah Media Office said: "The operations at the port are going as normal. Media outlets must be responsible and rely on official sources."
Calls and emails to Al Mayadeen and Sputnik for comment went unanswered on Sunday.
Al Mayadeen recently ran an interview with Hezbollah leader Hassan Nasrallah as he urged supporters to donate to his group and to wage war "by money".