WASHINGTON 

The US Embassy in Israel on Friday directed all US government employees and their family members to shelter in place "until further notice" as a result of the current security situation.

"The U.S. Embassy reminds U.S. citizens of the continued need for caution and increased personal security awareness – including knowing the location of the nearest shelter in the event of a red alert as security incidents, including mortar, rocket, and missile fire, and unmanned aircraft system (UAS) intrusions, often take place without any warning. The security environment is complex and can change quickly," it said in a statement.

It came after Israel launched a sweeping military operation against Iran on Friday, with strikes targeting its nuclear program and long-range missile capabilities.

Israeli Prime Minister Benjamin Netanyahu said in a speech posted on YouTube that his forces struck the "heart of Iran's nuclear enrichment program. We struck at the heart of Iran's nuclear weaponization program."

Netanyahu described the attacks as a "targeted military operation to roll back the Iranian threat to Israel's very survival."

US Secretary of State Marco Rubio said Israel took "unilateral action" against Iran.

"We are not involved in strikes against Iran and our top priority is protecting American forces in the region. Israel advised us that they believe this action was necessary for its self-defense," he added.