Shiite major says attacks show how insurgents are resorting to new methods . Police : Bomber had met at least twice with deputy security chief before blast . 15 people are killed , 15 injured in roadside attack in southeastern Karbala . Gen. Abdul Jabbar Rabei Muttar , deputy commander of security , at the security operations building in Samarra . Pilgrims on way to Karbala for Muttar , one of holiest days on Iraqi calendar .
Shiite major says attacks show how insurgents are resorting to new methods . Police : Bomber had met at least twice with deputy security chief before blast . 15 people are killed , 15 injured in roadside attack in southeastern Karbala . Pilgrims on way to Karbala for Muttar , one of holiest days on Iraqi calendar .