"With our souls, with our blood we die for Bashir," the protesters chanted as they marched through the streets of Khartoum towards the offices of the United Nations.
"The ICC does just what the European Union, the United States of America and Israel tell it to do," the protesters said in a statement delivered to the UN offices.
Most of the protesters were government workers or from unions linked to al-Bashir's ruling National Congress Party (NCP). The demonstration was organised by the government-backed Sudanese Student Union and other government groups.
Abdel Basit Sabderat, the justice minister, said the ICC was trying to ignite a fire throughout his country.
"[The] ICC is not just targeting the president of the country, but the stability of the Sudanese people because the president represents the nation," he told the crowd outside the cabinet office.
Sudan has said an ICC move against its highest officials could undermine attempts to end the conflict in the Darfur region. Two senior government officials told Reuters news agency that Sudan would probably seek Chinese, Russian and African support at the UN to help block a warrant for al-Bashir.
|Al-Bashir cheered supporters at a protest
rally in Khartoum on Sunday [EPA]
Fears have been voiced that naming al-Bashir could trigger a military response from either Sudanese forces or their proxies against UN and African Union (AU) peacekeepers, and embolden rebels from the Darfur region.
China is Sudan's largest weapons supplier and dominates Sudan's oil industry, which produces more than 500,000 barrels per day.
Abdel Moneim Mabrouk, Sudan's ambassador to the Arab League, said he was confident the pan-Arab body, which will hold an emergency meeting to discuss the crisis, would support Sudan.
"We are now mediating in all diplomatic channels to gain support ... and to stop this effort by the ICC which is an unprecedented move which will not only harm peace in Sudan but peace and stability in the whole region."AU warning
The AU has also voiced concern over the potential ramifications of the ICC indictment.
The organisation claims that a possible trial could jeopardise peace efforts in Darfur.
The AU's peace and security council met in Addis Ababa, the Ethiopian capital, on Saturday, issuing a statement which expressed "strong conviction that the search for justice should be pursued in a way that does not impede or jeopardise efforts aimed at promoting lasting peace."
The council said it had been briefed on the ICC's plans by the court's deputy prosecutor, and "reiterated the AU's concern with the misuse of indictments against African leaders".
Luis Moreno-Ocampo, the ICC chief prosecutor, said last month that Sudan's "entire state apparatus" was involved in an organised campaign to attack civilians in Darfur.
He also said on Thursday that a new case covering "crimes committed in the whole of Darfur over the last five years" would be opened on Monday, and that al-Bashir would be named among those linked to the violence in the region.
Sudan refuses to recognise the ICC or arrest warrants issued for Ahmed Haroun, the secretary of state for humanitarian affairs, and Ali Kosheib, an Arab militia leader.
It says it has established its own court to try Darfur cases.