The US Embassy in Cairo has released a security message warning its citizens of potential clashes on Saturday, the third anniversary of the 25 January 2011 revolution.

The embassy told its citizens "there might be groups gathering in both celebrations and protest" in the areas of Tahrir Square in downtown Cairo,  Rabaa Al-Adaweya Mosque in Nasr City, Nahda Square by Cairo University in Giza, as well as other universities and governmental institutions.

"Some groups or individuals may conduct acts of violence as a means of disruption or defiance. The government of Egypt is deploying a large security presence as a precaution," the statement read.

Saturday began with a small explosion in Cairo's Ain Shams district, targeting a police security center. No casualties were reported.

Four explosions rocked Cairo on Friday, the eve of the anniversary, all of which targeted police institutions and left six dead and at least 80 injured.

On Saturday morning, thousands of Egyptians began arriving at Tahrir Square and other major squares nationwide to celebrate the revolution's anniversary amid tight security and repeated promises from the interior ministry that all gatherings will be secured by the police in coordination with the army.

The day's celebrations are led by the Wafd Party, the Free Egyptians Party, along with Tamarod, the group that spearheaded the protests leading to the ouster of Islamist president Mohamed Morsi last summer.

An Al-Qaeda-inspired group, Ansar Beit Al-Maqdis (Partisans of Jerusalem), claimed responsibility for Friday's early-morning bombing of the Cairo Security Directorate. The group, which has claimed the deadliest militant attacks since former president Mohamed Morsi's ouster in July, warned Egyptians in an audio statement not to take to the streets on Saturday.

The Muslim Brotherhood, labeled a terrorist organisation by Egypt's interim government, denied any ties with Friday's explosions. The group stated that it is planning nationwide protests against what they deem a coup against Morsi, who hails from its ranks.

Meanwhile, the Way of the Revolution Front, a coalition of several political groups opposed to both the military and the Muslim Brotherhood, including the Revolutionary Socialists, the liberal 6 April Youth Movement and the Strong Egypt Party, plans to hold demonstrations along with other independent activists and advocacy groups. They will be marching from Mohandeseen's Mostafa Mahmoud Mosque and the Journalists' Syndicate in downtown.