Israel and Iran fired at each other on Monday while a missile reportedly targeted a part of Saudi Arabia housing a U.S military base. It's the most serious escalation since a ceasefire began two months ago and now threatens to plunge the Middle East back into war.

Israeli authorities said two waves of Iranian missiles had targeted the country. Explosions could be heard in central Israel as Israeli air defenses sought to intercept the incoming Iranian fire.

The Iranian attack came after Israel launched strikes on central and western Iran early Monday in response to missile fire from Tehran, in the most serious crossfire since an April 8 ceasefire was reached in the Iran war.

Tehran warned of retaliation after Israel struck Beirut’s southern suburbs on Sunday in defiance of Washington’s request days ago to stand down.

The Israeli strikes came in apparent defiance of President Donald Trump, who told Israeli Prime Minister Benjamin Netanyahu that he doesn’t think Israel needs to respond further.

Yemen’s Houthi rebels claim missile attack on Israel

The Iran-backed rebels also said that Israel-affiliated vessels would again be a target in the Red Sea.

The statement from Brig. Gen. Yahya Saree was broadcast on the Houthis’ al-Masirah satellite news channel.

It’s another new escalation as the nominal ceasefire in the Iran war is being challenged by crossfire between Israel and Iran.

Iran claims attacks, says it targeted military bases

Iran claimed the attacks on Israel, saying their fire targeted two military bases in Israel.

The Revolutionary Guard described the attack as being part of Operation Nasr, or “Victory.” The Guard said it launched the missile fire after Israel targeted radar sites in three areas of Iran, without elaborating.

The Israeli military says it hit petrochemical complex in Iran

Israel's military says it him a petrochemical complex in southwestern Iran. It did not provide details.

The semiofficial Fars and Mehr news agencies said Israeli strikes hit a petrochemical factory in city of Mahshahr in Khuzestan province. It did not elaborate on the damage done.

Israel issues all clear after a second wave of Iranian missiles

Israel issued an all-clear after warning of a second wave of inbound missiles from Iran.

It was the second alert without any interceptions being heard in the country.

The Iranian fire comes after Israel launched strikes on Iran early Monday in the most-serious crossfire since an April 8 ceasefire was reached in the Iran war.

Sirens sound near Israel’s main nuclear research site

Israel said it detected a barrage of missiles from Iran toward central and southern Israel on Monday morning. Loud explosions were heard over central Israel, and missiles also targeted southern Israel, near the city of Dimona and Arad.

The remote desert city of Dimona houses Israel’s main nuclear research center, which opened in 1958. Israel is widely believed to possess nuclear weapons, though its leaders neither confirm nor deny this.

Iran targeted Dimona and Arad during the last round of conflict, injuring more than two dozen people.

No impact or casualties in Israel from Yemen missile launch

Israel’s rescue services said there were no reports of casualties or impacts from the launch from Yemen.

Israel shuts down schools nationwide as conflict escalates

Israel’s military updated its guidelines for civilians on Sunday evening, limiting large gatherings and canceling school across the country.

It is the first time school has been canceled across Israel since the earlier round of fighting with Iran in April, though schools in Israel’s northern border had been closed for much longer due to the threat of Hezbollah fire.

Israel says missile launched from Yemen

Israel said Monday that it detected a missile launched from Yemen targeting the country. Sirens sounded across Israel after the Yemen missile fire warning.

Yemen is home to the Iranian-backed Houthi rebels. The Houthis have fired missiles at Israel during the Israel-Hamas war and later, but haven’t been fully involved in the Iran war.

Saudi Arabia sounds missile alerts

Saudi Arabia sounded missile alert sirens Monday morning in an area home to an air base that hosts U.S. forces. Saudi state media reported the alert around its Al Kharj governorate, home to Prince Sultan Air Base.

It did not elaborate. The alert came after Israel launched strikes targeting Iran.

President Donald Trump had urged Israel not to respond

Speaking to The Financial Times, U.S. President Donald Trump before the Israeli strike on Iran insisted he dictated terms to Israeli Prime Minister Benjamin Netanyahu on how the war should be prosecuted.

“He won’t have any choice,” Trump told the newspaper in a telephone interview. “I call the shots. I call all the shots. He (Netanyahu) doesn’t call the shots."

The White House did not respond to messages Sunday about the strikes and whether they were done in coordination with the U.S.

Iran closes airspace around Tehran’s Imam Khomeini International Airport, country’s main airfield, after Israeli attack.

Israel strikes central and western Iran

Israel says it strikes central and Western Iran after missile fire; Tehran says explosions were heard in several cities.