Hundreds of supporters of ousted Egyptian president Mohammed Mursi clashed with riot police in Cairo, Giza and Alexandria on Friday.
The Egyptian government recently passed a highly-criticised law limiting the right to protest. It says it is simply enforcing the law by breaking up illegal demonstrations.
In Alexandria, police used tear gas to scatter demonstrators who then retaliated with stones.
Earlier two soldiers were killed in the Sinai Peninsula carrying out a raid that also left three al Qaeda-linked militants dead – according to the army.
Security sources said the militants involved were from the same group which carried out a suicide bomb attack on the interior minister in September. He survived unscathed.