Hamas fires rockets amid Israeli air strikes on Gaza
Palestinian militants have fired more rockets at Israeli cities after Israel carried out dozens of overnight air strikes on the Gaza Strip.
Israel said it had intercepted 15 rockets on Wednesday, including eight over Tel Aviv, Ashkelon and Ashdod.
Reports from Gaza said at least eight people had been killed in the latest Israeli air strikes.
Gaza officials say 35 Palestinians have now died in the recent hostilities, with 150 more injured.
The officials say half of the casualties are civilians, a number of them women and children.
The military wing of Hamas has warned that all Israelis are now targets.
Israel has said it will expand its campaign against Hamas.
Israel's military said it had carried out 129 air strikes in Gaza on Wednesday, primarily targeting tunnels and rocket-launching pads.
It brings to 550 the number of sites in Gaza attacked as part of "Operation Protective Edge", including 31 tunnels and 60 rocket launchers.
The military earlier confirmed that it had targeted 118 concealed rocket launchers, 10 Hamas command-and-control centres and 10 tunnels in overnight attacks.
It said 117 rockets had hit Israel on Tuesday, with the Iron Dome interceptor system shooting down 20. Three rockets landed around Jerusalem.
Some 48 rockets were fired at Israel on Wednesday, the military said. Iron Dome intercepted two rockets above Tel Aviv on Wednesday morning, three over Ashkelon and three over Ashdod.
The town of Hadera 100km (60 miles) north of Gaza, was also attacked, with an M-302 surface-to-surface rocket, the furthest target so far reached.
Gaza health official Ashraf al-Kedra told AFP news agency that Israeli air strikes on Wednesday had killed four Palestinians in Shejaiya and two in Zeitun - both close to Gaza City - and two more in Beit Hanoun.
Analysis by the BBC's Kevin Connolly in Jerusalem
As the military temperature rises it becomes harder to see what the shape of any endgame between Israel and Gaza might look like.
Hamas will find it difficult to walk away from this round of conflict without something to persuade its own people that the death and destruction in Gaza has achieved something. It will want prisoners released as part of a deal. Israel will be reluctant.
The pressure of public opinion too weighs on Israel, which has talked in terms of a final end to the rocket threat from Gaza. That's a tall order when Israel itself estimates that Hamas has a stockpile of 10,000.
Such cycles of conflict have ended in the past of course - as recently as November 2012 - but for now the talk is of deterioration, when last week the buzzword was de-escalation. Egypt's intelligence services remain a possible go-between but for now there appear to be no moves towards peace. When an Israeli cabinet minister was asked if there were any, he said simply: "Not now."
Israeli Defence Minister Moshe Ya'alon said on Wednesday that the campaign against Hamas would expand in the next few days and "exact a huge price".
Israel has warned it may send ground troops into Gaza. It has authorised the call-up of up to 40,000 military reservists. Hundreds of reservists have already been drafted.
Mark Regev, spokesman for Prime Minister Benjamin Netanyahu, confirmed that the situation was more one of escalation than de-escalation.
He told the BBC the Israeli army was acting to "dismantle Hamas's military machine".
"We don't want to have some sort of band-aid solution whereby we have a quick fix, a ceasefire and then we only have rockets on Israeli citizens next week," he said.
Palestinian Authority President Mahmoud Abbas has demanded that Israel immediately stop the raids on Gaza and appealed for calm.
Regional media review
An editorial in Haaretz says Hamas has been sent "a sharp, clear message... However, the fear is that this message would develop into a wide-scale war, whose results it is impossible to predict in advance". Alex Fishman in Yediot Aharonot says the confrontation between Israel and Hamas "crossed the point of no return yesterday afternoon. Henceforth, none of the sides has any control: not on the timetables and not on the way this battle will end".
Palestinian commentators strike a defiant note. "The enemy will not succeed in dividing our people between those who resist and those who surrender... The all-out aggression it launches on the West Bank and the Gaza Strip rather unites our people," writes Fathi al-Bis in Ramallah-based Al-Hayat al-Jadidah. Yusuf Rizqah, on the website of Gaza-based Filastin, says: "President [Mahmoud Abbas] does not have a serious stance, while most Arab leaders kept silent... The resistance in Gaza knows what it wants: Either victory or martyrdom."
Hamas spokesman Abu Obeida said Israel had violated the Egyptian-brokered truce that ended exchanges in 2012.
"In the face of this aggression, we affirm that the Zionist enemy should not dream of calm and stability," he said.
'No safe haven'
The head of the Palestinian Centre for Human Rights in Gaza, Raji Sourani, accused Israel of deliberately targeting civilians.
He told the BBC: "There is no safe haven in this place and Palestinian civilians are once again in the eye of the storm and are paying heavily. Israelis.. are trying to pressure militant groups through targeting civilians."
Tensions rose last week with the murders of three young Israelis in the occupied West Bank and a Palestinian teenager in Jerusalem.
Israel says Hamas was behind the abduction and murder of the Israeli youths - a claim it denies.
A day after their funerals, the Palestinian youth was abducted in East Jerusalem and murdered. Police have arrested six Jewish suspects and say it seems the 16-year-old was killed because of his nationality.