Palestinian militants have attempted to hit Israel’s commercial capital, Tel Aviv, with missiles fired from Gaza.

Residents took cover after air raid sirens alerted them to a missile threat for the first time in two decades, but there were no casualties.

Israel’s defence minister authorised the call-up of 30,000 reservists.

Three Israelis were killed by rockets from Gaza earlier, while 15 Palestinians have been killed in two days of Israeli attacks on Gaza.

Israel said 274 missiles had been fired from the Gaza Strip into Israel since Wednesday afternoon, when an Israeli strike killed the military leader of Hamas, Ahmed Jabari.

While some of those missiles have been intercepted by Israel’s Iron Dome missile defence system, others have hit their targets, including a direct hit on a block of flats in the town of Kiryat Malachi.

Two women and a man living on the top floor were killed.

Israeli Defence Minister Ehud Barak said: “This escalation will exact a price that the other side will have to pay.”

However, Hamas prime minister, Ismail Haniyeh, condemned what he called Israel’s “ferocious assault” against Gaza.

“We here in Gaza will remain steadfast and unshaken,” he said in a televised statement. “We will fend off the aggression.”

“We are all confident in our intrepid resistance fighters who are now deployed on the front,” he said.

Late on Thursday, BBC correspondents in Gaza reported several massive explosions and missile fire in and around Gaza City as Israeli strikes continued.

The two rockets fired at Tel Aviv landed south of the city, in Rishon Lezion, and in the sea.

The armed wing of Islamic Jihad said it had fired an Iranian-built, Fajr-5 rocket at Tel Aviv.

“We have widened the range of the battle to reach Tel Aviv and what is coming will be greater,” the group said in a statement.

This is the first time Tel Aviv has been threatened by missiles since the 1991 Gulf War, when missiles fired by Saddam Hussein’s Iraq landed in the city.

The Times of Israel website says sirens were also sounded in the Tel Aviv suburbs of Bnei Brak, Givatayim and Ramat Gan.

Many of the 15 Palestinians killed in Gaza during a two-day Israeli aerial and naval bombardment were members of militant groups, but civilians – including four children – were also among the dead.

They included 11-month-old Omar, the son of Jihad Misharawi, a BBC Arabic picture editor.

Israeli PM Benjamin Netanyahu has said Israel will do “everything in its power” to avoid civilian casualties in the conflict with Hamas.

But he said Hamas was deliberately placing its rockets and missiles in civilian areas prior to launching them at Israel.

“There is no moral symmetry between Israel and the terrorists in Gaza,” he said during a televised news conference in Tel Aviv.

“Hamas deliberately targets our children and they deliberately place their rockets next to their children. Now despite this reality – and it’s a difficult reality – Israel will continue to do everything in its power to avoid civilian casualties.”

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