The U.S. State Department has maintained its highest travel advisory—Level 4: Do Not Travel—for Iran, explicitly warning that U.S. citizens risk arbitrary detention, torture and denial of consular support as anti-government protests have spread nationwide.

Attacking Iran with airstrikes is "on the table" as President Donald Trump weighs military options in the country, his press secretary said.

President Trump has been briefed on a wide array of military and covert tools that can be used against Iran that go well beyond conventional airstrikes, including cyber operations and psychological campaigns,

The comments came after President Trump said he was “ looking at some very strong options” to curb the Iranian authorities’ harsh repression of anti-government protests.

Hundreds of protesters have been killed by security forces in what may be the largest − and possibly most consequential − wave of protests in Iran since 2009, human rights groups say. The killings, difficult to verify because Iran has for days imposed a sweeping internet blackout,

In an interview with CBS News' Norah O'Donnell on Monday, Iran's exiled Crown Prince Reza Pahlavi said, "We need action to be taken."

President Donald Trump warns Iran against harming protesters as unrest in Tehran enters its second week.