(CNN) Gulf nations were behind the hacking of Qatar's official news agency in May, planting false stories that sparked a diplomatic standoff and embargo, Qatari security officials said Thursday in Doha.

The IP addresses responsible for the hacking "came from one of the siege countries," a short video screened at a press conference in Qatar's capital asserted, without specifying which nation.

Those IP addresses were located in the United Arab Emirates, said Lt. Col Ali Mohammed al-Muhanadi, head of the investigation committee.

The Middle East was plunged into one of its worst diplomatic crises in decades last month when the UAE, Egypt, Saudi Arabia and Bahrain announced they would be cutting ties to Qatar over its alleged support of terrorism

They were responding to online remarks by Qatar's leader, Sheikh Tamim bin Hamad Al Thani, in which he called Iran -- a key rival of Saudi Arabia's -- an Islamic power and described Qatari relations with Israel as good.

Qatar has maintained its emir never made the remarks and that hackers planted the quotes.

At Thursday's news conference, security officials said an uptick in activity was noted on the state news agency website in the hours before the stories were planted.

The hack was coordinated, and information was disseminated on the news agency and the government's social media channels immediately, officials said.

The hack was contained in about three hours on May 24, they said. During that time, the hackers took over the state news agency and social media accounts.

The investigators said they would submit their findings to prosecutors to decide what sort of action should be taken.

Qatar calls for end of embargo

Qatar's ambassador to the United States has called for an end to the ongoing "blockade" of his country by a coalition of Arab states, while defiantly stating it could live under the embargo indefinitely.

"There is no damage to our economy. Qatar is solid in its economy, and we are comfortable and we can continue like this forever," the ambassador, Meshal bin Hamad Al-Thani, told CNN.

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The four nations leading the embargo provided a list of 13 demands to the Qatari government, including shuttering the Al Jazeera media network and reducing diplomatic ties with Iran. Qatar's foreign minister said the list was "made to be rejected."

In an interview with CNN's Richard Quest, the ambassador said the crisis was counterproductive to the region and the fight against terrorism.

"The state of Qatar has demonstrated its constructive approach to resolve this crisis, and we have called many times to have a meeting to sit and discuss this ... so now it's up to the boycotting countries to decide and come to the table," he said.

Saudi Arabia softening on demands?

Those comments came as representatives for the four nations boycotting Qatar appeared willing to relax their strict demands slightly on the isolated state.

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At a briefing Wednesday in New York, Abdullah bin Yahya Al-Mouallimi, the Saudi Arabian ambassador to the United Nations, emphasized the importance of six principles for renewal of diplomatic relations with Qatar, which the boycotting nations agreed to July 5 in Cairo.

"There are principles, and there are tools (among the 13 demands)," the ambassador said, implying some may be negotiable.

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The six principles are much less strict than the original demands, and are made up of broad requests such as "suspending all acts of provocation and speeches inciting to hatred or violence," according to Bahrain's state media. They don't include any action against Al Jazeera.

During the briefing, Mouallimi again accused Qatar of financing terrorism and backing extremism in the region, accusations that Qatar firmly rejects.

When asked afterward whether the four countries were backing down on their 13 demands, the Saudi diplomat dismissed the idea.

"I didn't discuss the demands or giving up on those demands. I talked about the important thing now being the commitment to the six principles. ... That statement was the last one to express the comprehensive point of view of the participating countries," he said.

No talks scheduled

Still, there are no talks arranged between Qatar and the other nations despite US Secretary of State Rex Tillerson's efforts during a visit to the region earlier this month.

Speaking to reporters as his plane left Doha, Tillerson said any resolution "may take quite a while."

"There's a changed sense of willingness to at least be open to talking to one another and that was not the case before I came," he said.

Hajj limits

Meanwhile, Saudi Arabia said it will welcome pilgrims from Qatar for the Hajj, the annual pilgrimage to Mecca, but will impose some travel limitations.

Travelers will be allowed to enter the country through any airline except Qatar Airways, including those that depart from Doha, the Saudis said.