The commander of the Hamas' Izzedine al-Qassam Brigades was killed in the fighting, the sources said.
CNN: Palestinian fighting 'will burn all of us,' official says
2.
Gaza-based al-Aqsa TV said the al-Qassam Brigades had fired 10 Grad missiles into southern Israel "in retaliation for the occupation's crimes".
BBC: Hamas fires barrage of rockets into Israel
3.
Manned by militants from its Ezz al-Din al-Qassam brigades hitherto deployed against Israel, Hamas's internal security applies the brigades' blinkered codes to harness society.