Saudi Arabia and key allies on Monday cut ties with Qatar, the world's top seller of liquefied natural gas (LNG), accusing it of supporting extremism and sending shockwaves through the energy industry.

Saudi Arabia's General Authority of Civil Aviation (GACA) said on Monday it has banned all Qatari planes from landing in the kingdom's airports, following the worst rift in years among the Gulf countries.

Riyadh-based Al Ahli Saudi Football Club has terminated its sponsorship deal with Qatar Airways, just hours after the kingdom announced it was severing ties with Doha.

The cost of insuring exposure to Qatari sovereign debt rose to the highest level in two months on Monday after Saudi Arabia, Egypt, the United Arab Emirates and Bahrain severed ties with Doha, accusing it of supporting terrorism.

It is in Russia's interest to have a "stable and peaceful" situation in the Gulf, the Kremlin said on Monday, commenting on the decision by a number of Arab nations to sever diplomatic relations with Qatar.

Turkey's Foreign Minister Mevlut Cavusoglu said on Monday he was saddened by a rift between Qatar and other Arab states, and called for dialogue to resolve the dispute.

Yemen's internationally recognized government cut ties with Qatar on Monday, accusing it of working with its enemies in the Iran-aligned Houthi movement, state news agency Saba reported.

Libya's eastern-based government has followed regional allies in cutting diplomatic ties with Qatar, its foreign minister, Mohamed Dayri, said on Monday.

Qatar Airways said on its official website on Monday that it had suspended all flights to Saudi Arabia.

Saudi Arabian Airlines (Saudia) has suspended all flights to Qatar, it said on its official Twitter account on Monday, without providing further details.

A Saudi-led Arab coalition fighting Yemeni rebels announced Monday it was ending Qatar's membership as most Gulf countries severed ties with Doha amid heightened tension between the neighboring states, AFP reports.

Credit rating agency Moody's Investors Service is concerned that the rift between Qatar and other regional states could have an impact on Qatar's credit outlook, if trade and capital flows are disrupted, a senior Moody's analyst told Reuters on Monday.

Oil rose on Monday after top crude exporter Saudi Arabia and other Arab states cut ties with Qatar, driving up prices on concerns over increased tension in the Middle East.

Egypt on Monday announced it was cutting diplomatic ties with Qatar, accusing Doha of supporting "terrorism", as Saudi Arabia, Bahrain and the United Arab Emirates adopted similar measures.

The United Arab Emirates cut ties with Qatar on Monday, state news agency WAM reported, accusing its Gulf Arab neighbor of supporting extremism and undermining regional stability.

Qatar's stock market tumbled on Monday after Saudi Arabia, Egypt, the United Arab Emirates and Bahrain severed ties with Doha, accusing it of supporting terrorism.

Qatar said on Monday it was facing a campaign of lies and fabrications aimed at putting the Gulf Arab state under guardianship, after Saudi Arabia, the United Arab Emirates, Bahrain and Egypt cut ties with it.

Saudi Arabia, Egypt, the United Arab Emirates and Bahrain severed their ties with Qatar on Monday, accusing it of supporting terrorism.

Bahrain said on Monday it cut diplomatic relations with Qatar, accusing its fellow Gulf Arab state of backing terrorism and interfering in Bahrain's internal affairs.

Bahrain Press Association (BPA) condemned the decision issued today by the Bahraini Information Affairs Authority that suspended Al-Wasat newspaper until further notice.