Egypt announced on Monday that it was severing diplomatic relations with Qatar due to its ongoing support for terrorist ideologies and meddling in the internal affairs of Egypt.
The move was taken "in light of the continued insistence of the Qatari government on taking a stance against Egypt," the foreign affairs ministry said in a statement on Monday.
The ministry said the move followed "the failure of all efforts to persuade Qatar against supporting terrorist organizations, chiefly the terrorist Muslim Brotherhood organization, and harboring its leaders who have been convicted of terrorist attacks that targeted the safety and security of Egypt."
The Egyptian government also accused Qatar of interfering in the domestic affairs of Egypt and other countries in the region in a manner that "jeopardizes Arab national security."
The ministry said that Egypt would close its airspace and seaports to all Qatari transportation with a view to protecting its national security.
Egypt's announcement followed a similar anouncement from Bahrain early on Monday morning, with Saudi Arabia and the UAE quickly following suit, finally joined by Yemen and the eastern-based government of Libya.
Qatar has long faced criticism from its Arab neighborrs over its support of Islamists and alleged attempts to destabilize other states.
Historically, other Arab states have been concerned by Qatar's support for the Muslim Brotherhood, a Sunni Islamist political group outlawed by Egypt, Saudi Arabia and the UAE.
Gulf countries led by Saudi Arabia fell out with Qatar over its backing of former Egyptian President Mohamed Morsi, a Brotherhood member.
In March 2014, Saudi Arabia, the United Arab Emirates and Bahrain recalled their ambassadors from Qatar over the rift.
Eight months later, they returned their ambassadors as Qatar forced some Brotherhood members to leave the country and quieted others. However, the 2014 crisis did not lead to a cutting of transportation routes.
Qatar has also been linked to Al-Qaeda-linked terrorist groups and Daesh, which has been operating as an insurgent force in Syria, Iraq, Libya, Yemen and the north of Egypt's Sinai Peninsula.
Daesh-linked groups have conducted numerous terrorist outrages, including several recent attacks in Egypt that targetted Coptic Christians.