JERUSALEM — For the first time in more than three months, at least one rocket fired from the Gaza Strip landed in southern Israel early Tuesday morning, according to Israeli authorities, breaking a cease-fire that had been 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-mail 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 Saturday. The statement also said that Palestinians ''should resist their enemy with all available means.''
Palestinian officials have blamed 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. Israeli authorities said that an autopsy conducted 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,'' 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, 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; 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 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 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.''
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.
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 accused Israel on Monday of fomenting chaos.