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.
Hamas operates a separate militant group called the Izzedine al-Qassam Brigades.
CNN: Rocket strikes mall in Israeli city; at least 14 wounded
3.
The armed wing of Hamas, the Izzedine al-Qassam Brigades, said it would continue launching rockets into Israel if "the aggression continues, " a masked spokesman said in televised comments.