JERUSALEM | Israeli aircraft struck the Gaza Strip on Thursday in response to militant rocket and mortar attacks, stoking concerns that a grave new round of hostilities will fill the vacuum left by an impasse in Israeli-Palestinian peacemaking.
Two years of relative calm have been unraveling in recent weeks with acts of violence against Israelis - including a deadly bombing in Jerusalem on Wednesday that killed a British tourist - and Israeli reprisals against Gaza militants, which in one case killed four Palestinian civilians.
Militants operating near the Israeli border sent at least nine rockets and mortars - including two rockets that reached the city of Ashdod - flying at Israeli communities throughout the day, drawing an Israeli airstrike in retaliation. No injuries were reported on either side.
Defense Secretary Robert M. Gates called the rocket attacks "repugnant" and defended the Israeli attacks in the Gaza Strip as legitimate self-defense.
He spoke during a meeting with his Israeli counterpart, Ehud Barak, who said that "Israel will not tolerate these terror attacks and we will not allow terror to rise once again in the region."
Because of the superiority of Israel's military, its enemies consider hitting Israeli cities as the most effective strategy in a war against the Jewish state.
Israel's inability to halt the rocket fire has drawn public criticism, especially since Israel has spent an estimated $200 million developing a system that is meant to shoot down the short-range rockets that militants use.
Although officials repeatedly have promised the Iron Dome is ready to be deployed, it so far hasn't been used in the field.
Home Front Minister Matan Vilnai, who oversees civil defense, refused to discuss the holdup in an interview on Israel Radio Thursday.
Israeli security officials have said little about the investigations into Wednesday's bus stop bombing and the knife killings of five members of a family in a Jewish settlement in the West Bank two weeks ago.
Officials identified the victim of the Jerusalem bombing Thursday as Mary Jean Gardner, a 59-year-old British tourist who had been taking courses at Jerusalem's Hebrew University.
Police spokesman Micky Rosenfeld said there were gag orders preventing discussion of either investigation. He said only that Jerusalem police remained on a heightened state of alert.
The rising wave of violence has been the fiercest since Israel went to war in Hamas-ruled Gaza more than two years ago to try to curb years of frequent rocket attacks.
On Thursday, Israel filed a complaint with the U.N. about the rising wave of attacks on its citizens.
Before leaving for a brief trip to Russia, Israeli Prime Minister Benjamin Netanyahu warned militants not to test Israel's "iron will" and vowed a tough response. But he also expressed hope that calm would be restored.