Saudi Arabia and its allies unveiled a "terrorist" blacklist on Tuesday of 18 organisations and individuals suspected of links with Islamist extremism that they said had ties with regional rival Qatar.
The move by the four Arab governments came despite mounting international pressure to compromise in their weeks-old boycott of their fellow US ally.
Saudi Arabia, the United Arab Emirates, Bahrain and Egypt last month released a list of 59 people and 12 groups they alleged had links to Qatar, accused by the four states of ties to extremist groups in the region. Qatar has denied the allegations.
Tuesday's list blacklisted nine charity and media organisations and nine individuals "directly or indirectly linked to Qatari authorities" as "terrorist", read a joint statement released by the four states.
The Saudi-led bloc, which now blacklists 89 persons and organisations accused of ties to Islamist groups they say are backed by Qatar, also dismissed an amendment last week to Doha's counter-terrorism law as insufficient.
Saudi Arabia and its allies have been boycotting Qatar since June 5 in the region's worst diplomatic crisis in years.
They sealed the emirate's only land border, ordered its citizens to leave and closed their airspace and waters to Qatari flights and shipping.
They demanded that Qatar break its longstanding ties with the Muslim Brotherhood, blacklisted as a "terror group" by the four governments although not by the international community.
They also demanded that it close broadcasting giant Al-Jazeera and a Turkish military base, and fall in line with Saudi-led policy in the region, particularly towards Iran.
Qatar has dismissed the demands as a violation of its sovereignty and has received significant support from its ally Turkey.
The four governments on Tuesday blacklisted three organisations based in Yemen and six based in Libya accusing them of ties to al-Qaeda.
They also blacklisted three Qataris, three Yemenis, two Libyans and a Kuwaiti they said were implicated in "fundraising campaigns to support (former al-Qaeda affiliate) al-Nusra Front and other terrorist militias in Syria".
Qatar and its neighbours support opposing sides in the conflict in Libya between a UN-backed unity government in Tripoli and a rival administration in the east.