No one was injured, according to the Qatari Ministry of Defense.
President Donald Trump announced "major combat operations" against Iran on Saturday, with daytime strikes in the joint U.S.-Israel attack targeting military and government sites, officials said.
On Sunday, Iranian state television confirmed that Ayatollah Ali Khamenei was among those killed by airstrikes in Tehran on Saturday.
Iran is responding to the U.S.-Israeli operation with missile and drone attacks targeting Israel, regional U.S. bases and Gulf nations. American diplomatic facilities have also been attacked.
In Lebanon, Israel is intensifying its long-running strike campaign against the Iranian-aligned Hezbollah militia.
Watch special coverage on Nightline, "War with Iran," each night on ABC and streaming on Disney+ and Hulu.
In his address, President Donald Trump said: "Our objective is to defend the American people by eliminating imminent threats from the Iranian regime, a vicious group of very hard, terrible people."
President Donald Trump confirmed the U.S. military began "major combat operations in Iran," in a video posted on his social media platform.
Israel and the U.S. have launched a joint attack on Iran, according to two U.S. officials.
The attacks have begun and they are being described as not small-scale, according to one U.S. official.
-ABC News' Luis Martinez and Anne Flaherty
The U.S. embassy in Qatar has told Americans to shelter in place, saying "all embassy personnel [are] directed to shelter in place and all Americans in the country are encouraged to do the same."
"The U.S. Embassy in Qatar is implementing a shelter-in-place for all personnel," the statement said. "We recommend all Americans do the same until further notice."
Officials said that Americans should "find a secure location within your residence or another safe building. Have a supply of food, water, medications, and other essential items."
