Saudi Arabia, Egypt, the United Arab Emirates (UAE) and Bahrain put a further nine entities based in Yemen and Libya and nine people from several Arab countries on the blacklist, saying all were associated with Qatar.
"(The new list) comes as a disappointing surprise that the blockading countries are still pursuing this story as part of their smear campaign against Qatar," Sheikh Saif Bin Ahmed al-Thani, director of the [Persian] Gulf kingdom's Government Communications Office, said in a statement sent to Reuters.
"This latest list provides further evidence that the blockading countries are not committed to the fight against terrorism. As we have previously stated, all individuals with links to terrorism in Qatar have been prosecuted."
Sheikh Saif said Qatar constantly reviews its anti-terror laws to "remain on the front foot in the fight against extremism and terror financing".
The four countries severed relations with Qatar on June 5, accusing the major gas-exporting [Persian] Gulf state of financing terrorism, meddling in the affairs of Arab countries and cozying up to their arch-rival Iran.
They want Qatar to cut back ties with Iran, close down a Turkish military base in Qatar and shut the Al Jazeera TV channel, which they view as critical of their governments.
Qatar and Turkey have been important backers of the Muslim Brotherhood movement that has challenged entrenched Arab rulers. Qatar, however, said last month that charges of support for "Islamist militancy" "hold no foundation in fact".
Doha signed an agreement earlier this month with U.S. Secretary of State Rex Tillerson aimed at combating terrorism financing, part of a U.S. effort to end the worst rift between Western-allied Arab states for years.
In Tuesday's statement, the four countries accused Qatari, Kuwaiti and Yemeni nationals of helping raise funds for al Qaeda militants. Their blacklist now include three Yemeni charities, three Libyan media outlets, two armed groups and a religious foundation, some of which are already subject to U.S. sanctions.