A U.S. official says an elite Marine rapid response team is headed to Sudan in the wake of violence and protests against the embassy in Khartoum.

The deployment comes as Sudanese police opened fire on protesters trying to climb the walls of the U.S. Embassy.

The Marine unit, known as a fleet antiterrorism security team, was sent in response to Friday's violence and as a precautionary measure,

The move follows news that Marines arrived on the ground in Yemen to deal with the aftermath of another attack on the U.S. Embassy in the capital city of Sanaa. They arrived in addition to an earlier contingent dispatched to Tripoli.

Pentagon spokesman George Little told Fox News the team is in Yemen as a "precautionary measure."

The move comes amid reports that protesters jumped over U.S. Embassy walls in both Sudan and Tunisia. At least 3 people have been reported dead and another 28 have been wounded during the Tunisia attack, Reuters reports, citing state television. Reuters also reported that protesters set fire to trees and broke windows inside the U.S. Embassy compound in Tunis.

A senior U.S. official, without explaining the extent of the breach in the latter attack, told Fox News that Tunisian security forces "have responded effectively" so far to the incident.

"We're keeping a close eye on events there, but for the moment, the Tunisians are doing precisely what they should do in the face of such events," the official said.

One official also reportedly claimed that protesters in Sudan have been expelled. Witnesses said Sudanese police opened fire on those trying to climb the walls.

That is just a snapshot of the violent unrest playing out Friday, in the widest protests yet across the Muslim world.

The day of protests, which spread to around 20 countries, started small and mostly peacefully in countries such as Indonesia, Malaysia, India, Afghanistan and Pakistan. The most violent demonstrations took place in the Middle East. In many places, only a few hundred took to the streets, mostly ultraconservative Islamists -- but the mood was often furious.

One protester was killed in the northern Lebanese city of Tripoli in clashes with security forces, after a crowd of protesters set fire to a KFC and a Hardee's restaurant. Protesters hurled stones and glass at police in a furious melee that left 25 people wounded, 18 of them police.

Security forces in Egypt and Yemen fired tear gas and clashed with protesters to keep them away from U.S. embassies. And Germany's Foreign Minister says the country's embassy in the Sudanese capital of Khartoum has been stormed by protesters and set partially on fire.

A senior State Department official said Friday that the administration has stood up a 24-hour "monitoring team to insure appropriate coordination." The official said the team is working with missions around the world "to protect American citizens."

The intense demonstrations, purportedly by people upset over an anti-Islam film, follow warnings by the State Department that the protests could spread across the region. The department, on its Twitter account, cautioned Thursday of sustained protests in Egypt, Oman and Jordan, among other places.

The Department of Homeland Security and the FBI also issued a joint intelligence bulletin warning that the violent outrage aimed at U.S. embassies could be spread to America by extremist groups.

In a statement to Fox News, a DHS official said that there is no specific, credible information at this time to indicate that the attacks have increased the threat of violent reaction in the U.S., but it will continue to identify potential threats and take appropriate measures.

Four Americans were killed in an attack on the U.S. Consulate in Benghazi, Libya, on Tuesday. A Marine unit was dispatched earlier in the week to Tripoli, to help fortify the U.S. Embassy there in the wake of the attack in the eastern part of the country.

The Associated Press contributed to this report.