A rocket fired by militants from Gaza overshot the Israeli port city of Ashdod on Thursday afternoon, landing in an open area to the north, as Defense Secretary Robert M. Gates was meeting with Israel’s defense minister, Ehud Barak, less than 20 miles up the coast in Tel Aviv.

Rockets from Gaza have struck deeper into Israel this week than at any time since Israel ended its three-week offensive in the Palestinian coastal enclave in January 2009, and Israel has responded with repeated airstrikes against militant targets, raising fears that the recent escalation could spiral into an all-out conflict.

Mr. Gates joined Mr. Barak in condemning the attacks and underscoring the right of any sovereign state to defend itself.

“I would start by joining President Obama in condemning yesterday’s terrorist bomb attack in Jerusalem as well as the rockets and mortars fired into Israel from Gaza in recent days and even today,” Mr. Gates said at a news conference at the Israeli Defense Ministry. “We underscore that Israel, like all nations, has the right to self-defense and to bring justice to the perpetrators of these repugnant acts.”

Mr. Gates was referring to Wednesday’s bombing near the main bus station in Jerusalem — the worst attack in the city in four years — that killed a woman and injured at least 24 others.

Mr. Barak said that “Israel will not accept terrorism against its citizens” and noted that every sovereign nation “would respond when its citizenry became a target for indiscriminate launching of rockets.”

Still, several Israeli commentators said that while Israeli officials were issuing tough statements in an effort at deterrence, they were not eager to be dragged into an all-out confrontation.

Since Tuesday — when stray mortar fire killed four Palestinian civilians as Israel responded to a rocket attack, and the Israeli Air Force killed four Islamic Jihad militants who were said to be preparing to launch more rockets — Israel seems to have been practicing restraint.

An Israeli military spokeswoman said there had been one airstrike on Thursday morning against a squad of rocket launchers and another at night against a launching site. Gaza residents and security officials reported additional nighttime strikes against a sports hall, a Hamas training camp and other sites. There were no reports of casualties.

At least 10 rockets and mortar shells fired by Gaza militants slammed into southern Israel on Thursday. One struck the industrial zone of Ashdod, which is about 20 miles north of Gaza, and another hit the Israeli border town of Sderot. There were no reports of injuries, partly because Israelis in the south are used to running for cover as soon as they hear a rocket alert.

The bombing near the Jerusalem bus station on Wednesday has added to the Israelis’ sense of being under attack.

The woman killed in the blast was identified by the Israeli Foreign Ministry on Thursday as Mary Jane Gardner, 59, a Briton who was studying at the Hebrew University of Jerusalem. The British authorities confirmed that the victim was a British citizen and said that her family had been informed.

The relative calm in the south of the past two years ended on Saturday when Hamas, the Islamic militant group that controls Gaza, fired dozens of mortar shells at Israel, violating an informal cease-fire. There were signs that the Hamas military wing took action because of an internal dispute with the group’s political leadership. In recent days Hamas seems to have stepped back from the fighting, leaving the rocket attacks to Islamic Jihad and other militant groups.

With Israel’s prime minister, Benjamin Netanyahu, on a visit to Moscow, Israel did not seem about to embark on a major military campaign. Israeli commentators noted that given the impasse in the Israeli-Palestinian peace process, there would not be much international support for such an action.

“Lurking behind the laundered words that the prime minister chose to use last night — ‘we will operate forcefully, responsibly and wisely’ — is the fact that Israel currently has no international support as a result of the deadlock in the peace process,” the journalist Shimon Shiffer wrote in the newspaper Yediot Aharonot on Thursday. “And that is why its hands are tied insofar as a military operation is concerned that is liable to lead to the death of civilians.”

Mr. Gates said the violence was reason to push forward with the peace process.

“I know there may be a temptation during this time of great uncertainty in the region to be more cautious about pursuing the peace process,” Mr. Gates said. “But in my meetings with Israeli and Palestinian leaders, I carry a different message: that there is a need and an opportunity for bold action to move toward a two-state solution.”

He said the United States remained ready to support the peace process “in any way we can.”