Iran's internet was cut off late last Thursday, apparently in an attempt by government authorities to prevent protesters from organizing and uploading videos for the outside world to see. CBS News senior foreign correspondent Holly Williams has more on the protests and Andrew Boyd,

The protests, in which more than 500 people have died, have grown into a more serious threat to the Islamic Republic.

According to a U.S.-based human rights group, Iranian security forces are opening fire on protestors nationwide, reportedly killing hundreds of protestors and arresting thousands of others.

Nationwide protests have been shaking Iran for weeks. They started Dec. 28 in response to soaring prices, then turned into wider anti-government protests against the clerical rulers who have governed the country for nearly 50 years.

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,

U.S.-based human rights groups monitoring the protests in Iran estimate hundreds of demonstrators have been killed amid a communications blackout.

Protests continue in Iran, where more than 500 people have been killed since they started in late December, according to the rights group HRANA.

President Trump was briefed on military options in Iran as deadly anti-government protests continue, a U.S. official confirmed. CBS News' Holly Williams and Aaron Navarro have more details.