However, Qatar Airways said flights we operating as "normal".
Social media is a hugely popular medium of expression in the Arab world.
Saudi Arabia, United Arab Emirates, Bahrain, Egypt and Yemen cut diplomatic ties with the tiny Gulf state, accusing Qatar of harboring extremists and backing Saudi Arabia's regional rival, Iran. "This by itself is a violation of its [Qatar's] sovereignty as a state", Qatar's foreign ministry said in a statement.
Crisis in the Gulf: Why is Qatar under siege? Jordan has downgraded its diplomatic representation and revoked the license of Doha-based TV channel Al Jazeera.
The United Arab Emirates had already said Qatari nationals would not be allowed to enter the country or cross its points of entry, although the practical effects on airline passengers had been unclear until now. He called for Qatar "to become a neighbor and partner as we were accustomed to it".
For Trump, the rift has emerged as a key test of his goal to unite the region around destroying IS and other extremist groups, and containing Iranian influence.
Saudi Arabia's central bank advised banks in the kingdom not to trade with Qatari banks in Qatari riyals, banking sources said.
5-star Elite 11 QB Justin Fields decommits from Penn State
But losing the commitment of Fields will be a blow, should the 6-foot-3, 221-pound quarterback eventually decide to go elsewhere. Earlier this week Fields was announced as an Elite 11 finalists that showcases 11 of the nation's top quarterback recruits.
"In this respect, we appreciate Qatar's constructive stance", he said.
UAE Minister of State for Foreign Affairs Anwar Gargash threatened more curbs if necessary and said Qatar needed to make "iron-clad" commitments to change policies on funding militants.
Trump's recent speech in the capital Riyadh, in which he blamed Iran for instability in the Middle East and urged Muslim countries to take the lead in combating radicalisation, is seen as likely to have emboldened Gulf allies to act against Qatar.
A total of 27 flights from Dubai to Doha had been scheduled for Tuesday and the Dubai Airports website showed all flights to Doha had been cancelled. Navy Capt. Jeff Davis, a Pentagon spokesman, expressed gratitude to Qatar for supporting the US presence, outlining no plans to adjust American military posture.
Gulf Cooperation Council (GCC) have also blocked all transport and communication links with Qatar.
Qatar is also a major regional diplomatic player and global investor and is set to host the World Cup, football's biggest tournament, in 2022.
He suggested Qatar was funding extremism.
Russian President Vladimir Putin told Qatar's emir, Sheikh Tamim bin Hamad al-Thani, in a phone call that crisis situations should be solved by political and diplomatic means, "in dialog", the Kremlin said. "That's something that the Secretary spoke to as well", Nauert said in response to a question.
Qatar has an independent streak that has often angered its neighbours.
The coordinated move dramatically escalates a dispute over Qatar's support of the Muslim Brotherhood, the world's oldest Islamist movement.