CAIRO - Clashes are continuing between Egyptian security forces and more than 5,000 protesters in Cairo's Tahrir Square, leaving more than 590 injured, according to witnesses and medical officials.
Tahrir Square, the epicenter of protests that toppled Hosni Mubarak, Egypt's former president, was sealed off early on Wednesday as lines of security forces in riot gear strived to regain control from demonstrators.
Witnesses said the clashes started on Tuesday when police tried to clear a sit-in at the state-TV building, which included families of those killed during the country's revolution earlier this year, known as the "martyrs", according to the Daily News, an Egyptian news website.
Witnesses said police showed up and attacked the families outside the Balloon Theatre in Agouza, where a planned memorial service for the families was taken place.
The ministry of interior said in a statement on Tuesday that "people who claimed to be families of martyrs, tried to break into the theatre" in which the service was held.
Al Jazeera correspondent in Cairo Ayman Mohyeldin said: "The original dispute happened between families of the martyrs of the revolution as they were trying to attend an event [and were denied access].
"At that point there were clashes between police and some of those family members that ultimately spilled over to other parts of the city.
"The protest gained momentum and made its way into Tahrir Square, and ultimately to the interior ministry," he said.
Rocks and shattered glass littered the streets around Tahrir, as protesters chanted: "Down with the military junta."
Egyptian Prime Minister Essam Sharaf has said that he ordered the police to withdraw from Tahrir Square to reduce tension.
He also added that the performance of the police had been improving, and that some people may not be happy with the gradual return of police and security. But he "urged the youth to protect their revolution."
Our correspondent in Cairo said that police had been aggressive in pushing the crowd back.
He also added that they [police] had not withdrawn completely: "They have moved back from the centre, but they remain in the square."
The ruling military council issued a statement on its Facebook page released early Wednesday.
It said the Tahrir events aimed at disturbing the security and the stability of the country in an organised plan.
"The regrettable events that have been taking place at Tahrir Square since last night and till dawn today have no justification except to undermine stability and security in Egypt according to a calculated and coordinated plan in which the blood of the revolution's martyrs is used to cause a wedge between the revolutionaries and the security apparatus in Egypt to achieve these goals.
"We urge the great Egyptian people and the youth who launched the revolution not to be carried dragged by such claims, work on resisting and aborting them to maintain Egypt's security and safety in such difficult circumstances".
Families of those killed during the revolution have repeatedly voiced frustration with the slow pace of the trials of the policemen and officials accused of killing and ordering the killing of their relatives during the protests.
Our correspondent said:"The standoff between the police and the protesters has intensified given the last few months and the pace of the process towards a democratic and civilian government.
"Many Egyptians have been extremely frustrated by the wheels of justice not spinning fast enough."