Clashes between protesters and police broke out in the Egyptian capital Cairo yesterday as opposition groups organised a rally to mark the second anniversary of the uprising that ousted dictator Hosni Mubarak.

Scores of people are reported to have suffered injuries after police fired tear gas shells at demonstrators who tried to remove security barricades and demanded the resignation of President Mohammed Mursi.

The opposition groups shouted slogans like: "Down with Mohammed Mursi" and "Down with the power of the (Supreme) Guide". Protesters also hurled stones at the police.

The ruling Muslim Brotherhood's young brigade has reportedly been deployed around party offices to prevent any untoward incident.

However, despite the Brotherhood's efforts to quell the protests, opposition groups which accuse Mursi of "stealing the revolution" are planning to gather for further demonstrations in the focal Tahrir Square today. Thousands of people are expected to march to the venue soon after Friday noon prayers.

Other key Egyptian cities, including Alexandria and Port Said, are also likely to witness huge rallies.

"This 25 January anniversary will not be a celebratory one, but rather a new revolutionary wave to complete the revolution's goals," said Ahmed Maher, founder of the April 6 Movement, according to al Ahram online.

Liberal politician and Nobel Laureate Mohamed ElBaradei encouraged all Egyptians to take part in the protests, saying: "I demand from each one of you, all across Egypt, to prove that the revolution must continue and much be completed.

"Egyptians rose up for the sake of freedom, dignity and social justice. We must not stop until we see all the demands achieved. It will take time but we have to put ourselves on the right path."

Parties across the political spectrum are commemorating the second anniversary of the uprising. More than a dozen parties, including the Brotherhood, have organised programmes to mark the occasion.

The Brotherhood has not called for street rallies but has pledged to launch social initiatives. Mursi has urged Egyptians to "celebrate the revolution" in a peaceful way.

"We have to feel that we are all in one ship and we have to preserve its safety and respect the people and their free will which they express in their ballot boxes," Mursi said during his address.