Israel and Iran launched fresh attacks on each other overnight into Sunday, stoking fears of a wider conflict after Israel expanded its surprise campaign against its main rival with a strike on the world’s biggest gas field.

Tehran called off nuclear talks that Washington had said were the only way to halt Israel’s bombing, while Israeli Prime Minister Benjamin Netanyahu said the attacks were nothing compared with what Iran would see in the coming days.

Israel’s military said more missiles were launched from Iran towards Israel overnight, and that it was attacking military targets in Tehran.

Early Sunday morning, air raid sirens blared across Jerusalem and Tel Aviv. Several missiles were seen streaking through the sky over Tel Aviv, while interceptor rockets were launched from the ground. Explosions echoed in both cities.

Israel’s ambulance service said three women were killed and 10 other people injured in an earlier missile strike near a house in northern Israel. Emergency responders with flashlights were seen searching the rubble of the partially collapsed home in Tamra, a predominantly Palestinian city.

Around 2:30 a.m. local time, the Israeli military warned of another barrage launched from Iran and urged the public to seek shelter. By 3:30 a.m., at least four people had been killed and 36 were reported injured in multiple overnight missile attacks. Israeli media published an image of a 10-story residential building, reportedly in central Israel, showing extensive damage after a strike.

Iran said the Shahran oil depot in Tehran was targeted in an Israeli attack but that the situation was under control, and that a fire had erupted after an Israeli attack on an oil refinery near the capital. Israeli strikes also targeted Iran’s defence ministry building in Tehran, causing minor damage, Iran’s Tasnim news agency said on Sunday.

Iran’s Revolutionary Guards said Iranian missiles and drones targeted Israel’s energy infrastructure and facilities for fighter jet fuel production. The elite force warned Tehran’s attacks will be “heavier and more extensive” if Israel continues its hostilities.

US President Donald Trump had warned Iran of worse to come, but said it was not too late to halt the Israeli campaign if Tehran accepted a sharp downgrading of its nuclear programme.

A round of US-Iran nuclear talks that was due to be held in Oman on Sunday was canceled, with Iranian Foreign Minister Abbas Araqchi saying the discussions could not take place while Iran was being subjected to Israel’s “barbarous” attacks.

In the first apparent attack to hit Iran’s energy infrastructure, the semi-official Tasnim news agency said Iran partially suspended production at the world’s biggest gas field after an Israeli strike caused a fire there on Saturday.

The South Pars field, offshore in Iran’s southern Bushehr province, is the source of most of the gas produced in Iran.

Fears about potential disruption to the region’s oil exports had already driven up oil prices 9% on Friday even though Israel spared Iran’s oil and gas on the first day of its attacks.

An Iranian general, Esmail Kosari, said on Saturday that Tehran was reviewing whether to close the Strait of Hormuz controlling access to the Gulf for tankers.

IRAN SAYS SCORES KILLED

Iran said 78 people were killed on the first day of Israel’s campaign, and scores more on the second, including 60 when a missile brought down a 14-storey apartment block in Tehran, where 29 of the dead were children.

Iran had launched its own retaliatory missile volley on Friday night, killing at least three people in Israel.

With Israel saying its operation could last weeks, and Netanyahu urging Iran’s people to rise up against their Islamic clerical rulers, fears have grown of a regional conflagration dragging in outside powers.

B’Tselem, a leading Israeli human rights organization, said on Saturday that instead of exhausting all possibilities for a diplomatic resolution, Israel’s government had chosen to start a war that puts the entire region in danger.

Tehran has warned Israel’s allies that their military bases in the region would come under fire too if they helped shoot down Iranian missiles.

However, 20 months of war in Gaza and a conflict in Lebanon last year have decimated Tehran’s strongest regional proxies, Hamas in Gaza and Hezbollah in Lebanon, reducing its options for retaliation.

Israel sees Iran’s nuclear programme as a threat to its existence, and said the bombardment was designed to avert the last steps to production of a nuclear weapon.

Tehran insists the programme is entirely civilian and that it does not seek an atomic bomb. However the U.N. nuclear watchdog reported it this week as violating obligations under the global non-proliferation treaty.