CAIRO, Egypt - Police fired tear gas at supporters of ousted President Mohammed Morsi who were marching on a government building in central Cairo Tuesday, security officials said.
Hundreds of Muslim Brotherhood and Morsi supporters took part in the march on the country's Ministry of Religious Endowment.
The demonstrators were also pelted with rocks by some local residents.
Police said 12 pro-Morsi protesters were arrested after they tried to enter the ministry building.
There was no immediate information about casualties or fatalities.
It comes a day after Egypt’s interim government - installed on July 3 by army chiefs - said Morsi would be detained for a further 15 days pending investigations of charges he conspired in 2011 with Palestinian militants.
Morsi was elected to power by popular vote in 2012.