Dozens were injured on Tuesday in clashes between supporters of Egypt's ousted President Mohamed Morsi and security forces in downtown Cairo, amid conflicting reports as to who started the violence.

Skirmishes reportedly erupted when pro-Morsi demonstrators attempted to reach the headquarters of the Religious Endowments (Awqaf) Ministry in central Cairo.

Eyewitness said the clashes began when unidentified men on the roof of the ministry building began throwing bottles and stones at protesters below.

Security forces then fired teargas to disperse the demonstrators, chasing many of them into adjacent streets and holding several inside the ministry building, eyewitnesses added.

A ministry official, however, said the violence began when pro-Morsi protesters attempted to storm the building.

A field hospital in Cairo's Rabaa al-Adawiya Square, the site of a major pro-Morsi sit-in, said the clashes had left dozens injured.

The Muslim Brotherhood-led National Alliance for the Defense of Legitimacy, which called for the protests, said that an unspecified number of demonstrators had been arrested during the melee.

According to the alliance, marches set out from 28 mosques throughout the capital towards Rabaa al-Adawiya Square and Giza's Nahda Square, where pro-Morsi demonstrators have maintained sit-ins for 47 and 42 days, respectively.

The Tuesday marches are being held under the banner "Together against the Coup and Zionism," referring to Morsi's July 3 ouster and a Friday air raid that killed four militants in Egypt's Sinai Peninsula. Militant groups have blamed Israel for Friday's attack.

Ever since his removal early last month, supporters of Morsi – Egypt's first democratically elected president – have been staging daily mass protests and sit-ins to demand his reinstatement.

The Tuesday marches come amid increasing reports that authorities plan to soon begin dispersing the two main pro-Morsi protest sites.

The Egyptian government has said that it views the twin sit-ins as "a threat to the national security". Last week, it mandated the Interior Ministry – which controls Egypt's sprawling police apparatus – to take "all necessary measures" to disperse the demonstrations.

PHOTO CAPTION

Supporters of Egypt's ousted President Mohammed Morsi chant slogans during their sit-in around Rabaah al-Adawiya mosque, which is fortified with multiple walls of bricks, tires, metal barricades and sandbags, where protesters have installed their camp in Nasr City, Cairo, Egypt, Monday, Aug. 12, 2013.

AA