''Down, down USA, down down CIA,'' the crowd chanted, ''there is no God except Allah, the USA will not govern US''.
Others said: ''We want ambassadors of France, Italia and Britain out of this country to leave this country immediately.''
This was just a piece of the action as Sudan shows its disgust for the warrant issued by the Hague-based International Criminal Court for the arrest of President Omar Hassan al-Bashir. The warrant requires any country that has the powers to arrest the Sudanese leader and hand him over to the court for trial over war crimes in the country's Darfur region.
The UN claims that some 300,000 people have been killed in Darfur but, Sudan disputes this figure saying it is exaggerated.
Today, one could have been excused if you thought the rally was a rock concert or a gathering of ardent fans of a soccer team all out for one goal, victory. In this case, the one goal is that President Bashir must never be tried by the ICC.
The president opened his speech by saying that ''Sudan is strong, this day Sudan is happy.''
President al-Bashir, who arrived at the rally at 12.30 pm told of double standards that saw killings by Israeli forces in Gaza and killings by US forces in Iraq go unpunished.
To chants by the crowd estimated at close to a million, the president danced to traditional songs amid drumming as the crowd waved their walking sticks in the air.
What was clear was that the ICC had finally succeeded in uniting the entire Sudan behind their dear leader.
Flanked by second Vice-President Ali Osman Taha and other ruling party members, the President Bashir gave a long list of crimes that he felt should be addressed by the court as the crowd roared back.
The only sign that all was not well in Khartoum was the absence of Western journalists at the rally. Only Chinese, Arab and African journalists invited days earlier to cover the opening of a new dam were at the event held close to the president's palace.
No western journalists
But, the truth is that many Western journalists, always eager to be at the right place at the right time, were in the city but remained in their hotels for fear of attacks by the mobs at the rally.
To shouts of ''Takbir, Takbir, Allah Akhbar'' (God is great) the crowd waved sticks in unison with their leader who took power in a military coup in 1989, a fact long forgotten by many Sudanese who see him as a civilian leader.
In his speech, the President al-Bashir vowed to respond to the warrant wisely and without emotion.
This was an event where anyone armed with a slogan was free to shout it. The president's speech was interspersed by chants from the crowd, some lasting minutes.
All over the square, there were pickup trucks, with loudspeakers any stranger could pick a microphone and expresses his or her outrage over the court's decision.
So far there are no reports of attacks on Westerners in Khartoum save for some minor stoning of the US embassy and the UN office soon after the verdict was announced by the court.
But, as a sign that it will no longer be business as usual, the Sudan has already ordered 10 international NGOs to leave northern Darfur, among them Oxfam, the International Rescue Committee, Doctors without Borders and Care International.
The rally held today was the first since the ruling by the court. Earlier as President Bashir presided over the opening of the massive Merawi dam in the north of the country, he told the court that it could ''eat the warrant'' as it was useless.
More protests are planned in Khartoum especially on Friday after midday prayers.
Today's was a rather unique as it was the first reaction by the president to a move that may mean that he may end up one day in the cells of the ICC should any country sympathetic to the court lay its hands on him.
Sudan is not signatory to the Rome Statute that created the court.
But, despite the US's declaration that it supports the warrant for Mr Bashir, Washington does not recognise the ICC and has even passed a law in Congress that protects its military personnel from any trial by the ICC.
The Service Members Protection Act (ASPA), passed by the US Congress in 2002 authorises the US president to raid the ICC cells to free any American officer arrested by the court.
At the same time, ASPA requires countries that seek US military aid to commit never to aspire to hand over US troops to the ICC.
In the indictment, the court said: "There are reasonable grounds to believe that Omar al-Bashir is criminally responsible under article 25 (3) (a) of the statute as an indirect perpetrator or as an indirect co-perpetartor for war crimes and crimes against humanity and that his arrest appears to be necessary under the Rome Statute.''
The ruling was based on a request by Chief prosecutor Luis Moreno Ocampo. The court accepted Mr Ocampo's claims that President al-Bashir: "Intentionally directed attacks against a civilian population and was engaged in pillage, murder, extermination and forcible transfer as a crime against humanity.''
Now that the warrant has been issued, Sudan needs the support of its allies if there was to be any suspension of the order, a request that can only be issued by the UN Security Council.
Already, the African Union at its summit in Addis Ababa last month, called for suspension of the ICC warrant for 12 months.
China, which is a close ally of Sudan today urged on the UN Security Council to "respect calls by the African Union, Arab League and Non-Aligned Movement ... and call on the International Criminal Court not to hear this case for the time being".
In a statement by Mr Qin Gang, the foreign ministry spokesman, China said it "expresses its regret and worry over the arrest warrant for the Sudan president.''
China added that it is ''opposed to any action that could interfere with the peaceful situation in Darfur and Sudan."
In Cairo, Egyptian Foreign Minister Ahmed Aboul Gheit called for the suspension of the warrant. The minister urged the UN Security Council to "hold an urgent and emergency meeting" to defer the warrant against President al-Bashir.
Sudan has already given clear signs that it will not be cowed by the ICC ruling and President al-Bashir will maintain his normal schedule. The president plans to attend an Arab summit set for this month in Qatar.
Mr Mutrif Siddiq, under-secretary of foreign affairs said: "We have received the invitation and accepted it," Mutrif Siddiq, under-secretary of foreign affairs.
He added: ''President Bashir will attend all Arab summits and all African summits.'' In July this year, the African Union holds its heads of state summit in Antananarivo, the Madagascar capital and the Sudanese Foreign Ministry's position is that President Bashir will attend.
But the UN delegation in Khartoum is very worried by the decision taken by the court and views it as making their work more difficult. Before the ruling, there were fears that would be attacks on foreigners but no such event has taken place.
But, as the demonstrations pick up today, tensions could rise. The UN delegation here is on high alert.