JERUSALEM -- For the first time in more than three months, at least one rocket fired from the Gaza Strip landed in southern Israel early on Tuesday morning, according to Israeli authorities, breaching a cease-fire put in place after eight days of intense violence between Israel and Gaza last fall.
The Israeli police and military reported that a single Grad rocket landed in a road outside the city of Ashkelon, causing damage but no injuries.
A subgroup of the Al Aqsa Martyrs Brigade, the military wing of the Palestinians' Fatah faction, said in an e-mailed statement that it had fired the rocket in "an initial natural response to the assassination of prisoner Arafat Jaradat," a 30-year-old Palestinian who died in an Israeli jail on Saturday. The statement also said that Palestinians "should resist their enemy with all available means."
Palestinian officials have blamed Mr. Jaradat's death on what they described as "severe torture" during interrogation after his arrest Feb. 21 for throwing rocks at Israeli settlers in November. The Israeli authorities said that an autopsy conducted on Sunday could not determine the cause of death and that the bruising and broken ribs the Palestinians cited as evidence of torture could have been caused by resuscitation efforts.
Prime Minister Benjamin Netanyahu's office declined to comment on the rocket fire, but has generally held Hamas, the militant Islamic faction that has ruled the Gaza Strip since 2007, responsible for all attacks emanating from the territory. President Shimon Peres, who was visiting southern Israel on a previously scheduled tour, said, "Quiet will be met with quiet; missiles will be met with a response."
"I believe both sides have a deep interest in lowering the flames," Mr. Peres added.
Mushir al-Masri, a Hamas lawmaker, said in an interview that the statement from the Al Aqsa group was a "fabrication" and that Hamas "did not find that any of the working and known resistance groups have fired any projectile." In any case, Mr. Masri said Israel was "fully responsible for the consequences of the wave of the Palestinian public fury." He also accused Israel of violating the cease-fire first, citing several incidents in which Gazans have been shot near the strip's borders with Israel and fishermen attacked at sea; the Israeli authorities have said their soldiers and sailors were only responding to efforts to breach the new limits set out in the cease-fire agreement.
After the rocket fire Tuesday, Israel shut Kerem Shalom, the crossing through which commercial goods enter Gaza from Israel, and closed its Erez border crossing except for medical, humanitarian and "exceptional" cases, according to a statement from the military.
Sari Bashi, executive director of Gisha, a group that advocates for lifting Israel's restrictions on the Gaza Strip, protested the closures in a letter to Israel's defense minister, saying the timing raised "serious concern that this is not a travel restriction necessitated by a concrete and weighty security imperative but rather a punitive act aimed at Gaza's civilian population." She called the move "a dangerous regression to a policy that violates humanitarian law."
The rocket fire came after several days of demonstrations in Gaza and across the West Bank in solidarity with hunger-striking Palestinian prisoners and in protest of Mr. Jaradat's death. Many of the protests had been marked by clashes between the protesters and Israeli soldiers and settlers, with two Palestinian teenagers sustaining serious gunshot wounds on Monday at Rachel's Tomb, near Bethlehem.
During a rally Sunday in Gaza, Hamas officials had expressed frustration with its rival Fatah faction in the West Bank for not doing more to support the prisoners. Attallah Abu Al-Sebah, Hamas's minister of prisoner affairs, urged Fatah "to set the hand of resistance free to deter the occupation and stop its crimes against the prisoners," and called for kidnapping Israeli soldiers "instead of pursuing playful negotiations that brought nothing to the Palestinian cause."
Gal Berger, a reporter for Israel Radio who focuses on the Palestinian territories, said the rockets were "designed to signal that Gaza is not cut off from what goes on" in the West Bank, describing the attack as "lip service, to show that they are not sitting on the sidelines."
Mr. Berger said the three months of quiet since the Nov. 21 cease-fire signed by Israel and Hamas that ended Israel's Operation Pillar of Defense was the "most impressive exhibition of the complete control Hamas has" over other militant groups like Al Aqsa and Islamic Jihad, which have frequently fired rockets from the strip in recent years.
"There has not been one rocket fired from Gaza since the operation, and the recalcitrant organizations were there all the time," he said. "Now it is proven that the organizations can't fire unless Hamas lets them."
Adnan Damiri, a spokesman for the Palestinian security services in the West Bank, accused Hamas of wanting "to make chaos in the Palestinian territories" and working against the Palestinian Authority and its security force.
"The Palestinian leadership's position is not to allow dragging the Palestinian people into the circle of Israeli violence and to spare them an armed confrontation with the Israeli troops," Mr. Damiri said in an interview with Voice of Palestine radio. "Is there anybody who wants the Israeli tanks to enter in the Palestinian lands tomorrow or the day after and destroy what the Palestinian people have built?"
Israeli officials have been holding special security consultations about how to handle the changing landscape and have sent messages to the Palestinian leadership in the West Bank urging calm. President Mahmoud Abbas of the Palestinian Authority on Monday accused Israel of fomenting chaos.
Robert H. Serry, the United Nations special coordinator for the Middle East peace process, who has asked Secretary General Ban Ki-moon for an international investigation into Mr. Jaradat's death, on Tuesday issued a statement saying he was "deeply troubled by resumed indiscriminate rocket fire from Gaza, which is totally unacceptable."
In Washington, a State Department spokesman on Monday called on both sides to "exercise maximum restraint," a message he said was being conveyed directly to Israeli and Palestinian leaders.
"All parties should seriously consider the consequences of their actions, particularly at this very difficult moment," the spokesman, Patrick Ventrell, said at a news briefing. "We urge both Palestinians and Israelis not only to refrain from provocative actions that could destabilize conditions on the ground but to consider positive steps, just re-establish trust and de-escalate the current tensions."
Fares Akram contributed reporting from Gaza City.
This article originally appeared in The New York Times.