The rate has surged since the assassination Tuesday of Hamas leader Ahmed Jabari and an Israeli air offensive on the Gaza Strip.
The attack ends a period of calm that has prevailed since March and comes on the heels of Israel's return of the remains of 91 Palestinian militants.
Egypt's weakening control in the Sinai, from which militants launched attacks that killed eight Israelis yesterday, is a wild card in the policy of mutual deterrence between Israel and Hamas.
Women runners, including eventual winner Melissa Moon (front row c.), of Wellington, New Zealand, start the 33rd Annual Empire State Building Run-up in New York City on Tuesday.
A gun battle between Hamas and an Al Qaeda-inspired group that left about 30 dead last week is a sign of a growing movement inside the impoverished territory.
On his second trip to Israel, President Bush will address the issue of settlement building and try to push for progress on a two-state solution to the Israeli-Palestinian conflict.
President Abbas halted negotiations Sunday. Secretary of State Rice arrives this week.