Warning of a protracted fight, Israel and Iran carried out waves of deadly attacks Saturday, with neither side heeding international pleas for a de-escalation of hostilities.

In sweeping attacks that started early Friday, Israel has struck at the regime in Tehran, hitting Iranian nuclear and military assets. The Israeli strikes have killed at least 78 people, including nine senior scientists and experts, wounded more than 320 others and damaged Iran’s main nuclear site at Natanz.

Iran in turn has launched barrages of ballistic missiles and drones at Israel, targeting what it says are military assets, but with less apparent success. At least three people have been killed and dozens wounded in the attacks.

It is the most intense fighting in decades between the two heavily armed countries, and has stirred anxiety over the prospect of an increasingly deadly conflict that could draw in the United States and other major powers.

The salvos of missiles scuttled talks between the United States and Iran aimed at curbing or halting Iran’s progress toward obtaining a nuclear weapon. The sixth round of talks had been scheduled to resume Saturday in Muscat, Oman’s capital, but the Omani foreign minister said they were canceled after Israel’s strikes on Iran.

French President Emmanuel Macron spoke by phone with Iranian President Masoud Pezeshkian on Saturday, Macron’s office said.

Macron called “for the utmost restraint to avoid escalation,” the statement said.

The French president urged his Iranian counterpart to return to the negotiation table quickly: “The Iranian nuclear issue … must be solved through negotiation.”

Also Saturday, the leaders of Egypt and Turkey warned that Israel’s “escalatory approach” risks plunging the entire Middle East into “full-fledged chaos.”

A statement from the Egyptian presidency said President Abdel Fattah el-Sissi and his Turkish counterpart Recep Tayyip Erdogan stressed in a phone call that Israel’s attacks on Iran could lead to “catastrophic repercussions” in the region.

They called for an immediate cessation of military operations and a return to the Omani-mediated nuclear talks between the United States and Iran.

Israel has conducted roughly 150 strikes on Iran over two days, while Iranian forces have fired roughly 200 ballistic missiles at Israeli territory in addition to scores of drones, according to an Israeli military official.

Fars News, an Iranian outlet affiliated with Iran’s Revolutionary Guard, reported Saturday that Israel was widening its attack, striking oil refineries and energy infrastructure. Among the targets Israel struck was the South Pars gas field in the Bushehr province, which was on fire, the outlet reported. The Israeli military declined to comment.

Residents of Tehran, Iran’s capital, reported hearing explosions Saturday morning, and Iranian air defenses were activated. The Israeli military said it had conducted a wave of strikes against the air defenses around Tehran. Iranian state news media said that the Israeli targets overnight had included a military jet hangar at Tehran’s Mehrabad airport.

Across Israel, people huddled in reinforced bomb shelters as air-raid sirens wailed outside, warning of incoming missile fire. Loud explosions reverberated overhead as Israel’s anti-missile defenses intercepted many of the incoming missiles.

Meanwhile, President Donald Trump and Russian President Vladimir Putin held a 50-minute phone call Saturday to discuss the escalating situation in the Middle East, Putin aide Yuri Ushakov said.

During the conversation, Putin briefed Trump on his recent talks with the leaders of Iran and Israel and reiterated Russia’s proposal to seek mutually acceptable solutions on the Iranian nuclear issue.

Associated Press contributed.