Saudi Arabia has described criticisms by Qatar of restrictions on access of its citizens to the annual Hajj pilgrimage as a "declaration of war" as the diplomatic row in the Gulf escalates.
Saudi Foreign Minister Adel al-Jubeir told Al-Arabiya on Sunday night: "Qatar's demands to internationalise the holy sites is aggressive and a declaration of war against the kingdom.
"We reserve the right to respond to anyone who is working on the internationalisation of the holy sites," he said.
Qatari officials, however, have denied accusations by al-Jubeir that its officials called for changes in the status of how the annual pilgrimage is administered by Riyadh.
Qatari Foreign Minister Sheikh Mohammed bin Abdulrahman al-Thani said no official from his country had made such a call.
"We are tired of responding to false information and stories invented from nothing," Sheikh Mohammed told Al Jazeera TV.
Limited entry for Qataris
Qatar did, however, accuse the Saudis of politicising Hajj on Saturday during a meeting of the United Nations special rapporteur on freedom of religion.
The state-backed National Human Rights Committee (NHRC) told the UN that Qatari citizens were being told that they could only enter Saudi Arabia through two airports and that they would have to travel via the Qatari capital of Doha to be allowed in.
The NHRC said in a statement that it was "extremely concerned over [Saudi Arabia] politicising religious rituals and using [Hajj] to achieve political gains".
"The Saudi authorities have allowed the Qatari pilgrims to enter Saudi Arabia through two airports via Qatar only, thus any Qatari citizen located outside Qatar must first return to Qatar then travel to Saudi Arabia," it said.
According to Al Jazeera, the NHRC said it had filed a complaint with the UN special rapporteur over the restrictions, which it said were in "stark violation of international laws and agreements that guarantee the right to worship".
Qatar's foreign minister on Thursday accused Arab states of violating international law in their boycott of the country and described the UN as the "right place" for Doha to seek options to overcome measures imposed against it.
Saudi Arabia, Egypt, the United Arab Emirates and Bahrain severed relations with Qatar on 5 June, accusing the major gas-exporting Gulf state of financing terrorism and cosying up to their arch-rival Iran. Doha denies the charges.
On Sunday, foreign ministers of the four countries said they were ready for dialogue with Qatar if it showed a willingness to tackle their demands.
The four states have cut air and sea links with Qatar and sanctioned dozens of groups and individuals. The UAE said on Saturday that Qatar needed to change its policies before a dialogue could take place.
"The entire campaign represents a series of violations of international law," Qatar foreign minister Sheikh Mohammed bin Abdulrahman al-Thani told reporters after meeting UN Secretary-General Antonio Guterres.
"The state of Qatar is not going to spare any effort in order to overcome those violations and try to solve it through the right channels. The United Nations is the right platform to start from," he said without giving further details.
UAE ambassador to the United Nations Lana Nusseibeh said the measures taken were "entirely legal, justified and proportionate" and accused Qatar of grave violations.