The Qatari authorities have accused Saudi Arabia of jeopardising the annual Hajj pilgrimage to Mecca of Qatari pilgrims by refusing to guarantee their safety.
Saudi Arabia and its allies have been boycotting Qatar since June 5, accusing it of backing extremist groups, in the region's worst diplomatic crisis in years.
Saudi foreign minister Adel Al Jubeir told Al Arabiya news channel on Sunday accused Qatar of trying to "internationalise" the management of Hajj, describing such a move as an "aggressive act and a declaration of war".
On July 20, Riyadh said that Qataris wanting to perform this year's Hajj would be allowed to enter the kingdom for the pilgrimage, but imposed certain restrictions.
The Saudi Hajj ministry said Qatari pilgrims arriving by plane must use airlines in agreement with Riyadh.
They would also need to get visas on arrival in Jeddah or Medina, their sole points of entry in the kingdom.
The Qatari Islamic affairs ministry, in a statement published by the official QNA news agency on Sunday, said Saudi Arabia had "refused to communicate regarding securing the pilgrims safety and facilitating their Haj".
The ministry accused Riyadh of "intertwining politics with one of the pillars of Islam, which may result in depriving many Muslims from performing this holy obligation".
According to the statement, 20,000 Qatari citizens have registered to take part this year. The ministry said it denied claims by Saudi Arabia that Doha had suspended those registrations.
Mr Al Jubeir said that the kingdom “welcomes all Muslims from around the world who visit the country for their pilgrimage". He said Qatar was trying to distract people from the real issue at hand, in reference to Doha’s alleged funding of terrorist groups.
Hajj is to take place this year at the beginning of September.
Saudi Arabia and its allies Bahrain, Egypt and the UAE cut diplomatic ties and imposed sanctions on Doha in June, including the closure of their airspace to Qatari airlines.
The four Arab states accuse Qatar of supporting extremists and of growing too close to Shiite-dominated Iran, the regional arch-rival of Saudi Arabia.
