Even as anti-American violence eased Saturday around the Muslim world, tensions remained high -- stoked, in some nations, by the prospect of U.S. troops arriving to protect U.S. diplomatic missions.

The widespread protests connected to an online trailer for an inflammatory anti-Islam film privately produced in the United States were relatively thin and calm, and in some places nonexistent, on Saturday compared to earlier in the week.

Yet even with this relative break, the furor has not gone away completely, nor has concern over safety and security at U.S. embassies.

To that end, U.S. officials said earlier this week that Marine teams would be dispatched to protect U.S. diplomatic missions in Libya, Yemen and Sudan in the wake of anti-Western unrest in those countries.

But U.S. troops haven't necessarily been welcomed.

Yemen's parliament issued a statement early Sunday demanding U.S. Marines leave the Arab country immediately, calling the presence of any foreign forces -- and U.S. troops in particular -- "unacceptable."

Some leading politicians, like Ahmed al-Bahri of the opposition Haq party, warned that even a few dozen American troops could "open the doors of hell for Yemen and give terrorists an excuse." Others like Abdul Majid al-Zindani, president of Yemen's Cleric Committee, equated the U.S. troops arrival to a foreign occupation.

Zaid al-Thari, a political adviser to Yemen's ruling General People's Congress, speculated that the U.S. Marines recent arrival raises doubts about who was behind this week's attacks on the U.S. embassy in Sanaa that left four protesters dead.

"In the end of the day, the United States is benefiting more than all and was able to bring its forces inside Yemen," said al-Thari.

Even with the arrival of its troops, the U.S. government isn't taking chances in Yemen -- closing its embassy in Sanaa through Saturday, September 29, because of the threat of "potential demonstrations," according to the State Department.

Meanwhile, U.S. Marines that were to travel to Sudan have returned pending further talks with the government there, a U.S. official said.

State Department spokeswoman Victoria Nuland said Saturday that Washington has requested "additional security precautions" in Sudan, whose government "has recommitted itself both publicly and privately to continue to protect our (diplomatic) mission."

Sudan's foreign ministry turned down a U.S. request to send "special forces" to protect its embassy in Khartoum, saying Sudanese security forces would protect "the diplomatic missions (and) its guests," according to a report from the state-run Sudan News Agency.

Secretary of State Hillary Clinton has warned the United States will act to protect its diplomatic facilities if countries in question did not prevent violence and seek justice for attacks.

"Reasonable people and responsible leaders ... need to do everything they can to restore security and hold accountable those behind these violent acts," she said Friday. "And we will ... keep taking steps to protect our personnel around the world."

In Egypt, where violent protests began in earnest last Tuesday and continued to rage for days, government officials have recently criticized violence targeting the U.S. Embassy in Cairo and promised to protect it. Notably, too, the thousands who participated in these demonstrations represent a fraction of the roughly 11 million people in the Egyptian capital.

Still, statements from the Muslim Brotherhood -- the Islamist group that controls parliament and whose former leader of its political party, Mohammed Morsy, is now Egypt's president -- that are in English differ from those in Arabic, which tend to be less sympathetic to diplomatic missions and focus more on the inflammatory "Innocence of Muslims" video.

And anti-American sentiments remain high in certain places, as was evident at a protest outside a mosque Friday. Those participating accused the United States of supporting "international terror" and being an "enemy of God," with some chanting, "Obama, there are a million Osamas."

"Relations between countries of the so-called Arab Spring and the West have not yet taken complete shape," saying this is especially true with Egypt, Prime Minister Hesham Kandil said Saturday, according to the state-run MENA news agency.

On the ground Saturday night, there was a marked change in Cairo -- as relatively calm returned to the area around the U.S. embassy for the first time in nearly a week.