On Friday, Qatar's foreign minister described the blockade as a violation of worldwide law and said there was an attempt to mobilise global opinion against the Gulf emirate.
"Leaders pointed to Qatar - look!"
Al-Thani also rejected any notion of shutting down the Qatar-based al-Jazeera satellite news network, suggested as a demand of the Arab nations.
Within hours, Qatar's government in a statement dismissed the terror sanctions list saying it "reinforces baseless allegations that hold no foundation in fact".
Turkey has also promised to send food and water supplies to Qatar, if needed.
An initial report from Qatar's Interior Ministry late Wednesday said the website of the Qatar News Agency was first hacked in April with "high techniques and innovative methods".
Those two, Sa'd al-Ka'bi and Abd al-Latif al-Kawari, are among dozens of individuals and entities named Friday by Saudi Arabia and its three allies. In addition to the Muslim Brotherhood leader, Egyptian born-cleric Youssef al-Qaradawi, 25 other Egyptian nationals were included on the list.
"Indeed, our position on countering terrorism is stronger than numerous signatories of the joint statement - a fact that has been conveniently ignored by the authors". A Libyan extremist group and four Bahraini groups were also listed as terrorist cells.
Qatar said it led the region in attacking what it called the roots of terrorism, giving young people hope through jobs, educating hundreds of thousands of Syrian refugees and funding community programmes to challenge extremist agendas.
Speaking during a Security Council debate on the threat of terrorism, Egypt's deputy ambassador to the UN Ihab Moustafa accused Qatar of paying "up to $1 billion to a terrorist group active in Iraq in order to release members of its royal family kidnapped and detained in Iraq while on a hunting trip".
The statement said the Bahraini king and the Egyptian president discussed latest developments, noting that severing ties with Doha came only after attempts to dissuade it from supporting terrorist organizations.