Polling stations will open Tuesday and Wednesday as voting on the Egyptian new constitution takes place amid fears of violence.
The army and police have announced increased security measures.
In a speech to soldiers participating in securing the referendum, Defense Minister Sisi said "we will come out for a great mission related to the homeland and its future". He added "the referendum will take place in difficult conditions, but we always work in those circumstances, and we are ready all the time".
Egyptian security services also announced a state of high alert on the country's borders.
The Cairo Post