At least 14 people were killed in strikes on the Gaza Strip on Tuesday (local time), Palestinian officials said, as Israel threatened a lengthy offensive against militants whose rocket fire reached as far as Tel Aviv.
People ran for cover as sirens sounded in Israel's business capital, in the deepest attack from Gaza since hostilities flared three weeks ago. The military said its Iron Dome anti-missile system shot the rocket out of the sky.
Israel said a ground invasion of the Gaza Strip was possible, but not imminent, and it urged citizens within 40 km of the enclave to stay close to bomb shelters.
"We are preparing for a battle against Hamas which will not end within a few days," said Defence Minister Moshe Yaalon.
"We will not tolerate missiles being fired at Israeli towns and we are prepared to extend the operations with all means at our disposal in order to keep hitting Hamas."
The White House condemned rocket attacks against Israel and expressed support for Israel's right to defend itself.
"We strongly condemn the continuing rocket fire inside of Israel and the deliberate targeting of civilians by terrorist organisations in Gaza," White House spokesman Josh Earnest said at a news briefing. "No country can accept rocket fire aimed at civilians and we support Israel's right to defend itself against these vicious attacks."
A source in Benjamin Netanyahu's office quoted the prime minister as saying: "The IDF (Israel Defense Forces) must be ready to go all the way. All options are on the table, including a ground invasion."
Explosions echoed across the densely populated Gaza Strip, shaking buildings and sending plumes of smoke into the air. In residential areas, the crying of children could be heard as ambulance sirens wailed.
At least eight civilians were among the 14 dead, Palestinian government and medical officials said. On the Israeli side, rocket impacts wounded at least two people, medics said.
In the Israeli port city of Ashdod, motorists scrambled from their cars and raced for the relative safety of apartment block entrances as a siren sounded, a scene repeated in other Israeli towns near the Gaza Strip.
Live television showed a double-burst of smoke in the clear blue skies above the Tel Aviv as a rocket was intercepted. The Islamic Jihad militant group said it fired the projectile.
In a bold infiltration, four Palestinian gunmen from Gaza came ashore near Zikim, where a kibbutz and an army base are located, just across the border from the enclave. The Israeli military said its troops shot them dead.
CHAIN OF EVENTS
The surge in violence along the Gaza border - the worst since an eight-day war in 2012, when Tel Aviv was also targeted - followed a chain of events begun by the abduction of three Israeli youths in the occupied West Bank on June 12.
Angry at Israel's arrest of hundreds of Hamas activists, the Palestinians have launched more than 200 rockets from Gaza, the Israeli military said. Hamas has neither confirmed nor denied any role in the kidnapping.
The Israeli youths were found dead, as was a Palestinian teen abducted in East Jerusalem last Wednesday in a suspected revenge murder for which six Israelis have been arrested.
Hamas has threatened an "earthquake" against Israel. But a Palestinian source close to it said Hamas was ready to restore calm if Israel met conditions, including a prisoner release.
Setting out terms for a ceasefire, the source said Israel had to "stop all forms of aggression", recommit to a 2012 Egyptian-brokered truce and free prisoners it detained in the West Bank last month.
The Israeli military said that to support regular forces, it was calling up reserve troops out of a pool of 40,000 approved on Tuesday by the security cabinet. Some 1500 other reservists have already been mobilised.
In one Israeli attack overnight that destroyed a Gazan home and killed six people inside, the Palestinian Interior Ministry said the family had received a telephone call from an Israeli officer telling them to leave.
Locals said the house belonged to a Hamas member's family, and that people had been urged to congregate there as "human shields" to deter a second attack after it was targeted earlier.
A Hamas commander, was killed, along with three others, in a strike on the car they were travelling in, a pro-Hamas website said, identifying the senior Hamas man as Mohammed Shaaban.