Sudanese police fired tear gas at hundreds of worshipers who staged protests after Friday prayers in the capital Khartoum's twin city of Omdurman.
Angry citizens have taken to the streets in the capital and other cities since 19 December after a government decision to raise prices of bread.
Hundreds of worshipers in Omdurman chanted "Freedom, Justice, the people want the downfall of the regime" as they poured out of Al-Sayid Abdel Rahman mosque in Omdurman in Wad Nubawi area, witnesses told Radio Tamazuj.
Several activists said anti-government protests also erupted in Arkawit, Halfaya, Burri and al-Shigelab areas in Khartoum, as opposition groups and the association of Sudanese professionals call for more anti-government protests on Sunday.
Bashir, who came to power in a military coup backed by Islamists in 1989, blamed a foreign conspiracy for trying to destabilize his country, as demonstrations against his rule continue.
The demonstrations that began over bread prices have mushroomed into a nationwide protest.
Amnesty International said 37 protesters were killed in the protests. The government admitted that at least 19 people were killed.
Earlier this week, Bashir ordered an investigation into the violent protests.