Israel mobilized troops to border areas near the Gaza Strip on Thursday after Palestinian militants in the enclave stepped up rocket attacks on southern Israel, heightening tensions following the kidnapping and murder of three Israeli students and the suspected revenge killing of an Arab teenager in East Jerusalem.

Israel said the deployments were ordered as a defensive measure after dozens of rockets were fired into its territory from Gaza, which is ruled by the Islamist militant group Hamas. The Israeli military said that it responded Wednesday and Thursday with airstrikes on 16 Hamas targets in the strip, including rocket-launching sites and weapons warehouses.

A Health Ministry spokesman in Gaza said the airstrikes injured 10 people. In southern Israel, where residents were advised to stay in bomb shelters, the military said a residential building and kindergarten were damaged and one soldier was injured by rocket fire that continued into Thursday evening.

An Israeli military spokesman, Lt. Col. Peter Lerner, said the troop mobilization did not signal an intent by Israel to prepare for a military operation against Hamas, which Israel has blamed for the recent kidnapping and killings of three Israeli teenagers in the occupied West Bank. But he said any de-escalation in violence would need to start with Hamas, which reached a cease-fire agreement with Israel after an eight-day war in November 2012.

“We need to be prepared” for an escalation, said Lerner, who would not say how many or what kind of forces had been dispatched to the border areas near Gaza. The Associated Press reported that tanks, artillery and ground forces had been deployed.

Abu Ubaida, a spokesman for Hamas’s armed wing, the Izze­dine al-Qassam Brigades, accused Israel of breaching the cease-fire and said Hamas was prepared to fight if Israel launched a military assault on Gaza.

Israel “might make the decision to start the battle, but it will never be able to determine the track of that battle,” he said.

Clashes that began Wednesday between Palestinian protesters and Israeli security forces in the Shuafat area of East Jerusalem continued Thursday afternoon. Several hundred youths confronted Israeli security forces, throwing rocks and firecrackers and vandalizing parts of the light-rail line that runs though the neighborhood. Israeli police responded with tear gas and rubber bullets.

The cross-border fire and blame came as the family of Mohammad Abu Khieder, 16, prepared for his funeral, to take place after Friday prayers in East Jerusalem, an event that could fan tensions. Khieder was abducted and found dead Wednesday in what authorities are investigating as a killing possibly meant to avenge the deaths of the three Israelis.

His relatives said Thursday that they had hoped to bury him sooner, according to Muslim tradition, but that they were still waiting for Israeli forensics authorities to release the remains.

“It is like a dream, and you want it to be a dream,” Hussein Abu Khieder, the slain youth’s father, said in an interview. “My boy is sweet, and we have no problem with anybody.”

The father denied allegations that his son was killed as a result of family strife. “This is not a family dispute,” he said. “This is just what the Israelis are trying to spread.”

Although Israeli police have yet to determine whether the latest killing was a “nationalistic” or a criminal act, residents of Shuafat — where the Arab teen lived and where he was abducted — insisted that Jewish settlers were behind the grisly killing. Police found the teenager’s charred body Wednesday in a forest on the outskirts of Jerusalem.

Speaking at an Independence Day event at the residence of U.S. Ambassador to Israel Daniel B. Shapiro, Israeli Prime Minister Benjamin Netanyahu condemned Khieder’s killing, saying that “vigilantes have no place in our democracy.” He vowed to bring those responsible to justice.

Khieder was killed two days after the discovery of the bodies of the three Israeli religious students, who were abducted June 12 near a West Bank settlement. The bodies were found Monday in a shallow grave covered by rocks near the tense West Bank city of Hebron.

The killing of the three Israeli teenagers — Naftali Fraenkel, 16, Gilad Shaar, 16, and Eyal Yifrach, 19 — sparked national outrage and collective mourning in Israel.

Israel blames Hamas for the killings, and Netanyahu has vowed that it will “pay.” The Sunni Islamist group, which Israel, the United States and the European Union have labeled a terrorist organization, has denied involvement in the deaths of the Israeli teenagers.

The abduction of the three teens sparked an Israeli security sweep across the West Bank of a scope not seen in years. Israeli troops carried out numerous raids and arrested more than 400 Palestinians, mostly members of Hamas. Seven Palestinians were killed and almost 200 wounded between June 13 and July 1 on the West Bank, according to the United Nations’ aid agency in East Jerusalem.

With tempers running at fever pitch, incitement and racism have been rampant on Israeli social media. In response, Israeli police said they were launching an investigation into Israeli calls for revenge against Arabs, Israel Radio reported.

Sufian Taha in Jerusalem, Islam Abdul-Kareem in Gaza City and Daniela Deane in London contributed to this report.