Jerusalem (CNN) -- A barrage of rockets and mortars fired into southern Israel continued Sunday, the latest in a four-day escalation of violence sparked by a series of attacks on Israeli civilians and soldiers Thursday.
By noon Sunday, 20 incoming rockets had been reported by Israeli officials.
An eighth victim died from Thursday's attacks, Israeli police said Sunday. He was identified as Yitzhak Sela, a 56-year-old bus driver.
The attacks on buses, cars and security personnel killed six other Israeli civilians and one soldier and wounded more than 30 people, authorities said.
Since then, nearly 100 rockets have been fired into Israel, Israel Defense Forces spokesman Brig. Gen. Yoav (Poly) Mordechai said Sunday. At least one Israeli was killed in an attack in Beer Sheva, authorities said.
Mordechai blamed Hamas for the rocket attacks, saying it "is not a movement but rather a murderous terrorist organization supported by Iran."
Hamas has denied involvement in Thursday's attacks and accused Israel of looking for a pretext to attack Gaza.
The Israeli military has targeted 15 "terrorist infrastructure sites" in Gaza and intercepted "around 13 rockets," the IDF said in a statement.
Fifteen people, including three children, have been killed in the Gaza airstrikes, said Sami Zaqout of the Al Mezan Center for Human Rights. Forty-four others were injured, Zaqout said.
The office of Palestinian Prime Minister Salam Fayyad, in a statement Sunday, said Israel's "rogue behavior must end."
The Palestinian government "calls upon the Israeli government to cease and desist in its use of its unjustified aggression against the Palestinian people in Gaza and to respect international law and refrain from revenge, terror, and collective punishment tactics," the statement said.
On Sunday, an IDF airstrike north of Gaza City hit an abandoned Hamas police training camp, Hamas sources said. No injuries were reported.
Israeli authorities arrested dozens of men in Hebron and surrounding towns.
Among the 60 arrested was a member of the Palestinian legislative council and others known to either belong to or support Hamas, said Hebron Gov. Kamel Hamid.
The rockets and mortars fired from Gaza on Saturday forced more than 500,000 people into bomb shelters, Israeli defense officials said.
Thursday's string of attacks was the deadliest against the Israeli population in two years.
The attacks occurred about 20 kilometers (12 miles) from the Israeli city of Eilat, close to the Israeli-Egyptian border. Israeli soldiers exchanged gunfire with the assailants and killed seven militants, the military said.
Early Saturday, the Hamas military wing Izzedine al Qassam Brigades, announced it was ending a de facto two-year truce with Israel.
The series of attacks and airstrikes comes a month before Palestinian officials plan to make a bid for statehood in the United Nations.
"The retaliation in Gaza and what happened last night in Hebron is not acceptable," Palestinian negotiator Saeb Erakat said on Sunday. "What is happening right now is making us very sure that our strategy of getting full recognition from the United Nations is the right way to go because when we are a full member of the U.N., Israel will have to think twice before attacking us."
Israel seized Gaza, the West Bank and other territory during the 1967 Six-Day War.
President Barack Obama earlier this year called on negotiations between Israel and the Palestinians to be based on border demarcations pre-dating the 1967 war. Israeli leaders have been vehemently opposed to such a move.
On Saturday, the Mideast Quartet -- the United States, the United Nations, the European Union and Russia -- issued a statement voicing its concerns over "the unsustainable situation in Gaza as well as the risk of escalation" and the group of negotiators "calls for restraint from all sides."
Israel believes the attacks have their roots in Gaza, but are coming out of the neighboring Egyptian region of Sinai. Egypt denies the allegation, saying it has been cracking down on terror groups in its portion of the Sinai.
CNN's Marwah Jbara-tibi, Guy Azriel, Kevin Flower, Michal Zippori and Chelsea J. Carter contributed to this report.