Egypt and the United Arab Emirates have joined Saudi Arabia and Bahrain in cutting ties with Qatar, adding fuel to a diplomatic dispute in the Gulf region.
Saudi Arabia and Bahrain were the first to sever all diplomatic ties with Qatar, citing national security concerns.
The countries have blocked Qatar from their airspace and requested that all Qatari diplomats leave within 48 hours.
In a Foreign Ministry statement, Saudi Arabia accused Doha of sheltering and backing terrorist groups, promoting terrorist groups in the media, and supporting Houthi militia in Yemen.
Cairo blamed the Qatari government for "hostile attitudes," sheltering the Muslim Brotherhood on its soil, and backing terror groups threatening the country's national security.
Bahrain's Foreign Ministry accused the Qatari government of destabilising the country's security and stability and interfering in its affairs.
[Qatar has] spread chaos in Bahrain in flagrant violation of all agreements and covenants and principles of international law without regard to values, the law, or morals or consideration of the principles of good neighbourliness or commitment to the constants of Gulf relations, and in denial of all previous commitments
Qatari citizens have 14 days to leave Bahraini territories. Bahrain also recalled its diplomats from Qatar, it added.
Last month the website of Qatar's official news agency was allegedly hacked by unknown individuals who reportedly published statements falsely attributed to its emir, Sheikh Tamim Bin Hamad al-Thani.
The incident triggered a diplomatic row between Qatar and its neighbours, the United Arab Emirates and Saudi Arabia.