CAIRO
Muslims Brotherhood said at least 53 people including 5 children were killed and more than 300 others wounded when army troops and police fired on people outside the Republican Guards headquarters in Cairo.
The Egyptian Ambulance Authority later said at least 51 people were killed and 435 others wounded.
It was not possible to reconcile the conflicting death toll figures.
Muhammad al-Baltaji of Muslim Brotherhood said, "While people were performing morning prayer in front of Republican Guards Headquarters, security forces firstly threw tear gas bombs and then opened fire on protesters."
Egyptian army said a commander was killed and nearly 40 soldiers were wounded in clashes between protesters and army forces when protesters attempted to raid Republican Guards Headquarters.
Rabia al-Adewiyya Press Center called for urgent help and medics to be permitted in Rabia al-Adewiyya Square and Republican Guards Headquarters, where 2 million Morsi supporters were besieged, and some others were injured.
Army says about 200 gunmen arrested but gave no further details
Meanwhile Egyptian Armed Forces said one officer was killed and several soldiers were wounded in an attempt by “a terrorist group” to storm the Republican Guards headquarters in the early hours of Monday.
“An armed group tried to storm the Republican Guards headquarters and assault army and police forces, killing an officer and wounding several soldiers, “ the army said in a statement.
"About 200 gunmen were arrested with different caches of weapons and the other members of the group are being pursued.”
The statement gave no further details, including the number of gunmen killed.
The army warned against any acts of violence or sabotage against military installations or vital facilities in the country.
“Those who violate these rules will put their lives at risk and will be dealt with decisively and in accordance with the law.”
The Egyptian Ambulance Authority (EAO) said 42 people were killed and 322 were wounded outside the Republican Guards HQ.
The Muslim Brotherhood said at least 53 people, including five children, were killed and hundreds were wounded when army and police forces opened fire on peaceful protesters outside the HQ.
Loyalists of Morsi, Egypt's first democratically elected president, have been camping outside the building since he was overthrown by the army on July 3.
The head of the Constitutional Court has been sworn in as interim president under the army roadmap.
The shootings further emboldens pro-Morsi protesters
The stench of death and accounts of surviving protesters outside the Republican Guards compound are further emboldening thousands of loyalists of Egypt's ousted president, Mohammad Morsi, in the nearby Rabaa Al-Adawia Square.
With blood stains on their clothes, dozens of survivors moved back to the Rabaa square to tell their stories.
"We put our trust in the army and gave them our back while praying, but they killed us," said Abdel-Hadli Abdul-Mottaleb who was shot in the shoulder.
He asserted that they will continue their protests until Morsi is restored to his office.
"We will not be terrorized by bullets. We all are martyrs."
The army said one officer was killed and several soldiers were wounded in an attempt by "a terrorist group" to storm the compound.
Sami Ibrahim toured the square carrying the ID and the blood-stained clothes of an injured fellow protester.
"Sisi's soldiers shot him in the leg," Ibrahim said of fellow protesters Mahmoud Magdy Ismail, referring to military chief and Defense Minister Abdel Fatah al-Sisi.
"Though he was injured, they (soldiers) did not show him any mercy and took him to an undisclosed location."