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.

US Defense Secretary Robert 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.”

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 have repeatedly 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.

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.