Israel steps up air strikes on the Gaza Strip. It came after a surge in rocket attacks directed at towns in southern Israel.

In Gaza, Palestinian officials say at least five people were killed and at least 30 are injured.

Hamas slammed Israel for the escalation.

SOUNDBITE: HAMAS SPOKESMAN, SAMI ABU ZUHRI SAYING (ARABIC):

"We will continue to defend our people against these crimes. We warn the occupation not to continue it's crime against our people. And we assure that the resistance is ready to defend this aggression."

The Israeli military says in the past 24 hours alone, more than 100 rockets were fired at them from Gaza.

At a peace conference in Tel Aviv, President Shimon Peres:

SOUNDBITE: ISRAELI PRESIDENT SHIMON PERES SAYING:

"Hamas was offered by the Quartet to stop shooting, recognize Israel, declare that you are for peace and you will be legitimized. They refused all the three, instead they cut tunnels to shoot rockets and they are