The Saudi foreign minister, Adel al-Jubeir, told reporters that further steps against Qatar would be taken at the appropriate time and will be in line with global law.
He also described Doha's response as a "position that reflects a failure to realise the gravity of the situation".
"Yesterday, we arranged that the Qataris would meet our secret services... open all the books and show them when we have questions about certain people or structures", German Foreign Minister Sigmar Gabriel told Deutschlandfunk public radio Thursday, upon returning from a trip to Saudi Arabia and Qatar, as well as Kuwait - the mediator in the ongoing dispute between the two countries.
The Gulf Arab states required Doha to cut diplomatic relations with Iran, close the Turkish military base, eliminate Al-Jazeera TV channel, extradite all persons wanted in four countries on charges of terrorism and pay compensation.
Qatar has refused to comply with the 13 demands made by the Saudi-led quartet, so now the ball is in their court.
Qatar accused them of "clear aggression" today and said the accusations "were clearly designed to create anti-Qatar sentiment in the West".
Trump tweets he's sending in federal help for Chicago's gun 'epidemic'
Meanwhile, Chicago police say crime in the city has decreased from 2016, when there were 4,331 shooting victims and 762 homicides. Roughly 40 ATF agents have already been working with local and state police on reducing gun violence in the city.
Predictably the Saudi embassy in London categorically denied the claim but the accusation comes at a time when United Kingdom ministers are under public pressure to finalise their own report on UK-based Islamist groups, following a series of deadly bomb blasts carried out by religious extremists in the country.
The UAE State Minister for Foreign Affairs Anwar Gargash, however, has predicted more isolation for Qatar.
Saudi Arabia and the UAE used it to launch what the Qatari foreign minister called an unjustified blockade. Saudi Arabia has also sealed its land border with Qatar, geographically isolating the tiny Gulf state.
The Egyptian foreign minister went on to say that media outlets in Qatar were guilty of "glorifying terrorist activities".
In addition, Doha excludes the possibility of closing the Turkish military base, arguing that the Charter of Gulf Cooperation Council (GCCC) does not prohibit such cooperation with other countries.
US President Donald Trump, while flying from Washington to Europe for meetings in Warsaw and Hamburg, telephoned Wednesday with Egyptian President Abdel Fattah al-Sisi.
According to the White House, the US President "reiterated the need for all countries to follow through on their commitments at the Riyadh summit to stop terrorist financing and discredit extremist ideology".