The IDF says missiles have been launched from Iran toward Israel and that "defensive systems are operating to intercept the threat." It also warned citizens to "enter a protected space and remain there until further notice."

The IDF said during a briefing Sunday that it has struck "over 250 targets" in Iran since the beginning of strikes earlier this week. It says it is still actively conducting strikes in the country.

The IDF spokesperson also confirmed it struck Yemen Saturday night, targeting a Houthi leader, but cannot confirm whether the strike was successful. There were also projectiles fired from Yemen overnight toward Israel, according to the spokesperson.

The spokesperson warned that "there will be further launches and impacts in the coming days" toward Israel and advised Israelis to pay attention to sirens and alerts.

-ABC News' Jordana Miller

The State Department is authorizing the "voluntary departure of family members and some non-emergency U.S. government employees" from Israel amid the country's escalating conflict with Iran, officials said on Sunday.

The U.S. embassy's shelter-in-place order for U.S. personnel in Israel remains in effect "until further notice" as a result of the conflict between Israel and Iran, the State Department said in a notice.

"U.S. citizens who wish to depart should not delay in taking advantage of commercial transportation options," the notice said.

-ABC News' Chris Boccia

Iranian Foreign Minister Abbas Araghchi told a meeting of ambassadors in Tehran on Sunday that Israel's ongoing attacks on the country could not have happened "without the agreement and support of the United States."

"We have received messages from the U.S. through various channels over the past two days stating that the U.S. had no involvement and will have no involvement in this attack," he said during the meeting, which was broadcast by state media. "As I said, we don't believe the U.S.'s claim."

Araghchi also called on the international community to condemn Israel's attacks on nuclear facilities.

"This is perhaps the last red line of international law that the Israeli regime has crossed, and if the international community is indifferent to these red lines, it will certainly have consequences for all other countries," he said.

Araghchi said he had called for a meeting on Monday with the head of the International Atomic Energy Agency over attacks on the Natanz nuclear facilities.

Of Iran's own retaliatory strikes on Israel, the foreign minister said the attacks were "legitimate self-defense." He added, "If the aggression stops, naturally our reactions will also stop." Araghchi confirmed that Iran struck "economic" targets in Israel on Saturday night.

Araghchi also said Israel is responsible for the breakdown in nuclear negotiations with the U.S., its attack having scuppered planned talks in Oman on Sunday.

"It is perfectly clear that the Israeli regime does not want any agreement on the nuclear issue; it does not want negotiations; it does not want diplomacy; and the attack on Iran amid nuclear negotiations demonstrates the Israeli regime's opposition to any negotiations," he said.

-ABC News' Victoria Beaule

An Israeli military official told ABC News that the country's warplanes have been flying over Iran for 50 hours nonstop since the beginning of Israel's strikes on the country on Friday.

The Israel Defense Forces are still searching for missile sites and other targets as strikes expand, the official said. They did not say how long attacks are expected to continue.

Among those targets hit so far are Iran's Defense Ministry in Tehran, plus gas and oil sites near Bandar Abbas, which the official said were "dual-use" sites -- meaning for both civilian and military use.

The official confirmed that Israel has not hit the Fordow nuclear site, which is buried deep underground.

Before the operation started, Israel believed Iran had about 2,000 ballistic missiles, the official said. They did not say how many are believed to be remaining.

When asked if Iran's Ayatollah Ali Khamenei -- the country's supreme leader -- is a target, the official refused to answer.

-ABC News' Jordana Miller and Dada Jovanovic