Palestinian militants have indicated they are ready for a truce with Israel to defuse a growing crisis, after fours days of rocket strikes from the Gaza Strip into the south of Israel.
There was no immediate response from Israel, which has warned it is ready to ramp up its air strikes and shelling if the rockets do not stop.
Leaders of Hamas, the Islamist faction that controls Gaza, met with Islamic Jihad and other groups this evening.
They said they would respond according to the way Israel acted - a formulation used in previous flare-ups to offer a ceasefire.
Throughout the day, Israel warned it was ready for stronger action.
Prime Minister Benjamin Netanyahu convened foreign ambassadors in what an apparent move to pre-empt international censure should Israel, whose 2008-2009 Gaza offensive exacted a high civilian toll, again go in hard.
Mr Netanyahu briefed the envoys in Ashkelon, a port city within range of some Palestinian rockets. "None of their governments would accept a situation like this," he said.
He was due to convene his close forum of nine senior ministers tomorrow to decide a course of action.
Israel Radio said Defence Minister Ehud Barak and military chief Lieutenant-General Benny Gantz had met with Mr Netanyahu tonight to present possible attack scenarios.
Environment Minister Gilad Erdan, an influential member of the Likud party, said the briefing was meant to prepare world opinion for "what is about to happen", adding there might be a major Israeli escalation within a few hours.
Hamas took part in some missile launches at the weekend but it did not claim responsibility for attacks earlier today, suggesting it was looking to step back from the brink.
The Israeli military said Palestinians had fired 12 rockets today and a total of 119 had been launched since Saturday.
Mr Netanyahu said a million Israelis - around one-eighth of the population - were in danger.
Israel has been deploying its Iron Dome rocket interceptor, air raid sirens and blast shelters, but eight people have been wounded by the rockets.
Six Palestinians, including four civilians, have been killed by Israeli shells fired on Gaza since Saturday, and at least 40 have been injured.
Israel has shown little appetite for a new Gaza war, which could strain relations with the new Islamist-rooted government in neighbouring Egypt. The countries made peace in 1979.
However Mr Netanyahu may be reluctant to seem weak ahead of a 22 January election that opinion polls currently predict he will win.
Israel said the latest flare-up started on Thursday with a fierce border clash.
On Saturday, a Palestinian missile strike wounded four Israeli troops patrolling the boundary, triggering army shelling of Gaza in which the four civilians died.
In turn, dozens of mortars and rockets were launched at Israel, which carried out a series of air strikes in Gaza.