The Cairo Opera House announced that it is suspending all concerts across all of its venues -- Cairo, Alexandria, and Damanhour -- for three days "in solidarity with the martyrs of Sinai." 

The concerts will be resumed on Monday 2 February, according to a statement published on social media.

At least 30 people, including civilians, were killed Thursday when a series of militant attacks, involving car bombs and mortar rounds, struck several army and police positions in Egypt's volatile Sinai Peninsula.

Cairo Opera House management added that all tickets issued for activities scheduled on Friday, Saturday and Sunday will be reimbursed.