The Lebanese Health Ministry announced that 50 people have been killed and over 300 have been injured in Israeli strikes since Monday.

The U.S. embassy in Amman, Jordan, announced it is canceling appointments until further notice and has instructed personnel to shelter-in-place.

"The embassy has instructed all Mission personnel to shelter-in-place. We recommend all Americans do the same," the alert on Wednesday said.

Canadian Prime Minister Mark Carney told reporters the U.S. and Israel's actions in Iran may be "inconsistent with international law."

"It's for the United States and Israel to make the case, and whether or not that is the case," he said. "It is for others more expert than me -- I'm not a lawyer, certainly not an international lawyer -- who are more expert to make that determination."

Carney said Canada regrettably supports efforts to prevent Iran from obtaining a nuclear weapon "because the current conflict is another example of the failure of the international order."

"Despite decades of United Nations Security Council resolutions, the tireless work of the International Atomic Energy Agency, and a succession of sanctions and diplomatic frameworks, Iran’s nuclear threat remains," Carney said. "And now the United States and Israel have acted without engaging the United Nations or consulting with allies, including Canada."

Carney called for a "rapid de-escalation of hostilities."

"Resolution of this crisis requires commitment to a broader political solution," he said. "Diplomatic engagement is essential to avoid a wider and deeper conflict."

The Al Udeid Air Base -- the largest US military base in the Middle East -- was struck by a ballistic missile from Iran, the Qatari Ministry of Defense said early Wednesday local time.

No one was injured, it said.

A second ballistic missile launched from Iran was intercepted, the defense ministry said.

The CIA had been tracking Iran's Ayatollah Khamenei for months prior to Saturday's U.S.-Israeli attacks on Iran, a source familiar with the intelligence confirmed to ABC News.

When they learned there would be a meeting of top leaders on Saturday with the Supreme leader, the timing of the attack was moved, the source said, adding that the agency had high confidence in their analysis.

These details were first reported by The New York Times. Khamenei was killed in Saturday's attacks.

A second source told ABC News that Israel had been planning for months with its own intelligence to target Iranian leadership, according to a person familiar with the operation.

-ABC News' Cindy Smith and Anne Flaherty