An Israeli air strike has destroyed a 13-storey residential block in the Gaza Strip, triggering a Hamas threat to fire 130 rockets into Tel Aviv and its suburbs.

Israel threatened yet more air strikes and has tanks massed on the border of Gaza in the worst escalation in violence since 2019. Israel last invaded Gaza in 2014 to stop rocket attacks.

Video footage showed three plumes of thick, black smoke rising from the tower, its upper storeys still intact as they fell.

The tower houses an office used by the political leadership of Gaza’s Hamas rulers.

Electricity in the area around the building went out and residents were using flashlights.

The wreckage of the “Hanady” at Al-Rimal building. It is unclear how many died. Photo: Getty

Shortly after the attack, Hamas and the Islamic Jihad group said they would respond by firing rockets at Tel Aviv.

Air raid sirens and explosions were heard around the city and Channel 12 television said there had been a direct rocket hit on a building in the suburb of Holon. Israel halted all flights from Tel Aviv’s Ben Gurion airport.

“We are now carrying out our promise,” Hamas’ armed wing said in a statement.

“The Qassam Brigades are launching their biggest rocket strike against Tel Aviv and its suburbs, with 130 rockets, in response to the enemy’s targeting of residential towers.”

Smoke billows from Israeli air strikes in Gaza City. Photo: Getty

Israel masses tanks on Gaza’s border

Hours earlier, Israel had sent 80 jets to bomb Gaza and massed tanks on the border as rocket barrages hit Israeli towns for a second day, deepening a conflict in which at least 28 people in the Palestinian enclave and two in Israel have been killed.

Residents of the block and people living nearby had been warned to leave the area about an hour before the air strike, according to witnesses.

It was not immediately clear if the building had been fully evacuated or if there were casualties.

The most serious outbreak of fighting since 2019 between Israel and armed factions in Gaza was triggered by clashes between Palestinians and Israeli police at Jerusalem’s al-Aqsa Mosque on Monday.

The holy city of Jerusalem has been tense during the Muslim fasting month of Ramadan, with the threat of a court ruling evicting Palestinians from homes claimed by Jewish settlers adding to the friction.

Relatives of Palestinian Ahmed Al-Shenbari mourn during his funeral. Photo: Getty

PM promises more air strikes

Prime Minister Benjamin Netanyahu said Israel would step up its strikes on Gaza, an enclave of 2 million people, in response to the rocket attacks, which carried on into the early evening.

“Both the strength of the attacks and the frequency of the attacks will be increased,” he said in a video statement.

Within an hour, Israel said it had deployed 80 jets to bomb rocket launch sites in and around Gaza City.

Officials said infantry and armour were being dispatched to reinforce the tanks already gathered on the border, evoking memories of the last Israeli ground incursion into Gaza to stop rocket attacks, in 2014.

28 Palestinians and two Israelis killed

On Tuesday, before the block collapsed, the Gaza health ministry said at least 28 Palestinians, including 10 children, had been killed and 152 wounded by Israeli strikes since Hamas on Monday fired rockets towards Jerusalem.

Israel’s ambulance service said two women had been killed in rocket strikes on the southern city of Ashkelon.

The International Committee of the Red Cross urged all sides to step back, and reminded them of the requirement in international law to try to avoid civilian casualties.

French Foreign Minister Jean-Yves Le Drian condemned the rocket attacks from Gaza into Israel but also said he was concerned at the threat of forced eviction of Palestinian residents in the Sheikh Jarrah neighbourhood of East Jerusalem.

– AAP