Protesters march urging action after a pupil was killed and three more children were wounded in a knife attack in a school in Zagreb, Monday, Dec. 23, 2004. (AP Photo)

Protesters hold placards urging action after a pupil was killed and three more children were wounded in a knife attack in a school in Zagreb, Monday, Dec. 23, 2004. (AP Photo)

Protesters march urging action after a pupil was killed and three more children were wounded in a knife attack in a school in Zagreb, Monday, Dec. 23, 2004. (AP Photo)

Protesters march urging action after a pupil was killed and three more children were wounded in a knife attack in a school in Zagreb, Monday, Dec. 23, 2004. (AP Photo)

Protesters march urging action after a pupil was killed and three more children were wounded in a knife attack in a school in Zagreb, Monday, Dec. 23, 2004. (AP Photo)

Protesters march urging action after a pupil was killed and three more children were wounded in a knife attack in a school in Zagreb, Monday, Dec. 23, 2004. (AP Photo)