71 killed in Israeli attack on Iran prison, official says

The State Department has issued a new worldwide caution alert prompted by the conflict between Israel and Iran.

"The conflict between Israel and Iran has resulted in disruptions to travel and periodic closure of airspace across the Middle East. There is the potential for demonstrations against U.S. citizens and interests abroad. The Department of State advises U.S. citizens worldwide to exercise increased caution," the alert reads.

Earlier this month, the State Department issued a regional alert related to the conflict, advising Americans in North Africa and the Middle East to exercise increased caution.

-ABC News' Shannon Kingston

The Justice Department currently has "countless" open investigations into threats to the U.S. homeland, Attorney General Pam Bondi said Monday in testimony to lawmakers on the House Appropriations Committee.

When asked about the presence of potential Iranian "sleeper cells" being activated in the U.S. in the wake of the military's strikes on Iran's nuclear program, Bondi said she couldn't answer such a question in an unclassified setting.

"I can't talk about that in this setting but what I can tell you is I know Homeland Security, I know the FBI -- they are focusing on doing everything we can to keep our nation safe, and they will continue to do that," Bondi answered. "Yeah, it's a frightening time in which we live right now, but President Trump is committed to keeping all Americans safe, and we look forward to working with you on that."

Bondi further confirmed that the department believes "well over 1,000" Iranian nationals entered the country illegally over the "last several years" and the department is on "high alert" regarding any potential illegal activity by those in the U.S.

-ABC News’ Alexander Mallin

Qatar Airways said it's temporarily suspending all flights following the closure of air traffic in Qatar.

"We are working closely with government stakeholders and the relevant authorities to support any passengers that have been impacted, and will resume operations when the airspace re-opens," the airline said in a statement.

No other U.S. bases in the Middle East have been attacked besides Al Udeid Air Base in Qatar, according to a U.S. official.

There are no reports of any damage to Al Udeid at this time, the official said.

While Iran is claiming it fired 14 missiles -- the same number of Massive Ordnance Penetrator bombs used by the U.S. in this weekend’s attack on Iran -- the official said the U.S. is still determining how many missiles were fired by Iran today.

-ABC News’ Luis Martinez