Israel moves forces near to Gaza as boy's funeral delayed
Israel has deployed extra forces along the border with the Gaza Strip amid heightened tensions with the Palestinians.
Israel says the move is part of its response to mortar and rocket fire from Palestinian militants from Gaza.
Earlier on Thursday, Israel launched air strikes against the territory.
Tensions are high after the murders of three Israeli teenagers in the West Bank and the murder of a Palestinian youth in Jerusalem.
Ten Palestinians were injured in the Israel Defense Forces bombardment of Gaza, which followed barrages of rockets from the territory into southern Israel.
Sirens were sounded in communities across the south of Israel, sending residents running to bomb shelters. A soldier was reported to have been slightly injured in Eshkol.
It was after an especially intense barrage of rocket fire in which two homes in the southern Israeli town of Sderot were hit, that Israel sent tanks, artillery and ground forces to the Gaza border area early on Thursday, defence officials said.
Prime Minister Benjamin Netanyahu said Israel would only act against further rocket attacks.
"We are ready for two options in the south. If fire toward our towns in the south ceases, then so shall our actions. The second option is that if fire toward our residents in the south continues, then our bolstered forces there will act forcefully," he said.
A spokesman for the armed wing of the Palestinian group Hamas, which runs Gaza, warned Israel against taking "foolish steps" and promised retaliation for any assault on Gaza.
In east Jerusalem on Thursday, masked Palestinians threw stones and fireworks at Israeli police in a second day of protest over the kidnap and murder of 17-year-old Mohammed Abu Khdair. Police responded with tear gas and rubber bullets.
The teenager's funeral has been delayed so that a post-mortem examination can be completed. His family said police had told them his body would be released early on Friday, Reuters reports.
His murder is being investigated but there are claims it was an act of revenge for the killing of the three Israeli youths in the West Bank.
Analysis: Kevin Connolly in Jerusalem
Israel's air attacks on Gaza should not be seen as part of any action it may be planning to take against Hamas for the kidnapping and murder of the three young Israelis buried earlier this week.
They were an immediate response to a wave of attacks from Gaza in which rockets and mortars were fired at southern Israel.
Israeli military sources say the targets were weapons manufacturing facilities and training sites used by the militant groups Hamas and Islamic Jihad.
But the exchange of fire comes at a time of rising tension in Israel and the occupied territories.
The funeral of Mohammed Abu Khdair had been due to take place after noon prayers at about 13:00 local time (10:00 GMT).
As the time for the burial approached, the family appeared to accuse the Israeli authorities of holding the body unnecessarily - something denied by police.
The post-mortem examination, which is being conducted by Palestinian and Israeli doctors, is reported to be taking longer than expected because the body was burnt.
The Palestinian teenager was seen being forced into a car in Shufat, East Jerusalem, early on Wednesday.
His body was later found in West Jerusalem.
Palestinian President Mahmoud Abbas accused Jewish settlers of killing the boy, calling for the "strongest punishment against the murderers".
Mr Netanyahu said the murder was "despicable" and that he had ordered police to work "as quickly as possible to find out who was behind the heinous murder of the youth".
Israeli and Palestinian media reaction
Ben-Dror Yemini in mass circulation Israeli daily Yediot Aharonot: "The Jewish majority hope, pray, that Jews did not murder the youth from Shufat... but there is a fear that we are in denial...that a cancer of racist right is nesting among us."
Dan Margalit in free, pro-Netanyahu Yisrael Hayom: ""Certainly every decent Israeli wants to get rid of the murderers of Eyal Yifrach, Naftali Frenkel and Gilad Shaer. There is a blood debt with the two Palestinians who murdered them...the IDF and the Shabak must hunt them, not wild groups who operate outside public life."
Pro-Fatah Palestinian daily Al-Quds: "We say once again that peace is the only way leading to the suspension of violence, fanaticism and tension."
Dr Isam Shawir in Hamas-run, Gaza-based Filastin: "The threats made by the occupation are worthless and do not scare Hamas, particularly in the Gaza Strip."
The family of one of the three murdered Israeli teenagers also issued a statement condemning the latest killing.
"If the Arab youth was murdered because of nationalistic motives, then this is a horrible and horrendous act," the statement from the family of Naftali Frenkel said.
Israeli police have urged caution over the motives for the killing, saying they are still investigating.
The bodies of the three Jewish seminary students were found near the city of Hebron on Monday, two-and-a-half weeks after they were abducted. Their funerals took place on Tuesday.