Rockets are lighting up the sky on the border of Israel and the Gaza Strip.

Weeks of escalating unrest have turned even more deadly.

Now residents of Gaza are digging out from the destruction, with a death toll of at least 20 people.

An aerial bombardment by Israel Tuesday may be just the start of a new offensive against Islamist militants.

Israeli Prime Minister Benjamin Netanyahu:

(SOUNDBITE) (Hebrew) ISRAELI PRIME MINISTER, BENJAMIN NETANYAHU, SAYING:

"Israel is in the middle of an operation to return security to our region. We will not tolerate the firing of missiles on our cities. I have ordered a significant broadening of the army's operation against Hamas and the terrorists of other groups in the Gaza Strip."

Hamas had vowed to strike further inside Israel after Israeli airstrikes killed six people in a home belonging to a member of the group.

Another group from Gaza, the so-called Palestinian Factions group, has blamed Israel for