Israeli aircraft attack targets in Gaza following rocket strikes against Tel Aviv carried out by Islamist militants.

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There were more than 25 air strikes on Thursday night, according to Reuters witnesses. One attack targeted an electricity generator feeding into the house of the Hamas prime minister in Gaza, Ismail Haniyeh. A police station and tunnels on Gaza's border with Egypt were also hit.

Earlier, Hamas and Islamic Jihad fired two rockets at Tel Aviv. One hit the suburb of Rishon Lezion, triggering air raid sirens. The other landed in the sea, according to Israeli security sources. No-one was hurt.

They were the first rocket attacks on Tel Aviv since 1991. The Israeli armed forces are preparing to call up 30,000 reserve troops, as speculation mounts that a ground offensive in Gaza is being considered.

Meanwhile, Egypt's prime minister and security officials will make a one-day visit to Gaza on Friday in a show of support for the Palestinian enclave after several days of shelling by Israeli forces, a cabinet source told the Reuters news agency.

At a press conference, Israeli Prime Minister Benjamin Netanyahu said: "Israel has made it clear that it will not tolerate rocket and missile attacks on its civilians.

"I hope that Hamas and the other terror organisations in Gaza got the message. If not, Israel is prepared to take whatever action is necessary to defend our people."

But Mr Netanyahu said he would try to avoid civilian casualties.

The Israeli army says three people in Israel were killed by a Hamas rocket following the bombardment of Gaza by Israeli aircraft, tanks and naval gunboats.

Hamas fired dozens of rockets into southern Israel, killing three people, following reported numerous airstrikes by Israel across the Gaza Strip.

Israeli police said the three died when a Palestinian rocket hit a four-storey building in the town of Kiryat Malachi, some 25 km north of Gaza. They were the first Israeli fatalities of the latest conflict to hit the coastal region.

Israel on Wednesday assassinated Hamas's military chief Ahmed al-Jaabari and shelled the enclave from the land, sea and air, killing 15 people, including five militants, three children and a pregnant woman. An estimated 100 were wounded.

Terrified residents on both sides of the frontier holed up at home in anticipation of heavy fighting on the second day of Israel's offensive against Gaza.

Gaza schools were ordered closed until the operation ends, and most of the territory's 1.6 million people were expected to stay indoors close to home, venturing out only to buy food, fuel and other basic supplies.

'Widen the operation'

The UN Security Council held an emergency meeting late on Wednesday to discuss the Israeli assault. It called for a halt to the violence, but took no action. Mr Netanyahu, who is facing an election at the beginning of 2013, said on Wednesday the Gaza operation could be stepped up.

"We've sent a clear message to Hamas and to other terrorist organisations," Mr Netanyahu said in a televised address on Wednesday evening. "And if there is a need, the Israeli Defence Forces are prepared to widen the operation. We will continue to do everything to defend our citizens."

His cabinet has granted authorisation for the mobilisation of military reserves if required to press the offensive, dubbed "Pillar of Defence" in English and "Pillar of Cloud" in Hebrew.

The assault came after a week of surging cross-border violence and defied hopes that Egypt had brokered a truce.

Within hours of a missile destroying Jaabari's car, militants fired a slew of rockets against the Jewish state's desert south.

Israel's military reported that its Iron Dome interceptor had shot down more than 30 of the missiles.

Egypt, whose new Islamist-rooted government pledged to honour the 1979 peace treaty with Israel, condemned the new Israeli raids as a threat to regional security. It recalled its ambassador from Israel and called for an emergency session of the UN Security Council.

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