Minor scuffles are ongoing around Cairo's Tahrir Square between pro- and anti-military protesters on the second anniversary of the Mohamed Mahmoud Street clashes.
Earlier in the afternoon, security forces fired tear gas outside the nearby Egyptian Museum, and formed barricades between the rival groups.
Tens of pro-military protesters gathered early Tuesday morning around the base of a memorial being erected by the interim authorities to commemorate those killed during Egypt's revolution, prompting clashes with anti-military protesters.
Hundreds of anti-army demonstrators had converged earlier in the morning in Mohamed Mahmoud Street, off Tahrir Square, waving national flags and holding aloft banners with the names of those killed in the clashes. They shouted slogans condemning the army and the police.
Anti-army demonstrators strung large banners across the Mohamed Mahmoud-Tahrir intersection reading "Revolutionaries only - no entry for Brotherhood, military or feloul (remnants of old regime)," and "Bread, freedom and cleansing the interior [ministry]."
Some 47 people were killed and at least 3,000 injured in days of clashes beginning on 19 November 2011 between anti-military council protesters and security forces. Protesters condemned heavy-handed police tactics and called on the then-ruling Supreme Council of the Armed Forces (SCAF) to step down.
Meanwhile, troops sealed off Ain Shams University campus after clashes erupted on Tuesday between students for and against toppled Islamist president Mohamed Morsi.
Armoured vehicles were stationed around the university gates, which is in eastern Cairo, as security forces erected barbed wire, Al-Ahram Arabic news website reported.
Students plan to march from universities in Cairo and elsewhere to mark the November 2011 clashes. These include the universities of Cairo, Ain Shams, Mansoura, Tanta, Damanhour and others.
On the first Mohamed Mahmoud anniversary, violence erupted between protesters and police, killing at least three.
Mohamed Morsi's Muslim Brotherhood has warned its supporters to steer clear of protests so "plotters" cannot blame Islamist for any violence.
Egypt's interior ministry has warned protesters to be watchful of infiltrators who might "disrupt [Tuesday's] event or derail its goals," stressing it "respects remembering all the martyrs."