Updated at 3:20 p.m. ET: President Barack Obama on Saturday rejected any denigration of Islam, but insisted there was no excuse for attacks on U.S. embassies as angry protests over an obscure, anti-Muslim film spread to Australia.
"I have made it clear that the United States has a profound respect for people of all faiths," Obama said in his weekly radio address.
"Yet there is never any justification for violence .... There is no excuse for attacks on our embassies and consulates,” he added.
Anti-American protests have swept the Muslim world in response to the film, which insults the Prophet Muhammad.
The death toll as a result of violence during protests in the Middle East and North Africa Friday rose from seven to nine with Tunisian officials saying four people -- rather than two as stated earlier -- died there. Three were killed by gunfire and the other died after being hit by two police cars, a senior hospital official told Reuters.
An attack on the U.S. Consulate in the Libyan city of Benghazi killed U.S. Ambassador Christopher Stevens and three others this week.
A day after Obama led a somber ceremony marking the return of the bodies of the Americans killed in Libya, Obama acknowledged that a surge of anti-American violence in the Middle East is disturbing.
The Pentagon had said it was sending Marines to beef up security at the U.S. Embassy in Sudan, following similar reinforcements to Libya and Yemen. But on Saturday, Sudan rejected the U.S. request to send a platoon the embassy in Khartoum.
"Sudan is able to protect the diplomatic missions in Khartoum and the state is committed to protecting its guests in the diplomatic corps," Foreign Minister Ali Ahmed Karti told SUNA, the state news agency.
Protesters on Friday entered the embassy grounds.
The Libyan attack and theU.S.-directed outrage have raised questions about Obama's handling of the so-called Arab Spring, a series of revolutions that have unseated entrenched authoritarian governments.
The turbulence in the Middle East has had ripples in a tight U.S. presidential election, with Obama's Republican challenger Mitt Romney saying Obama has weakened U.S. authority around the world.
However, Obama repeated a vow to bring the attackers of the U.S. Consulate in Libya to justice. "We will not waver in their pursuit," he said.
The president also said the turmoil should not deter U.S. efforts to support democracy in the region or elsewhere.
"Let us never forget that for every angry mob, there are millions who yearn for the freedom, and dignity, and hope that our flag represents," he said.
The protests over the anti-Islam film, "Innocence of Muslims," continued Saturday, spreading to Australia where authorities seemed taken by surprise as more than 400 demonstrators gathered outside the U.S. Consulate in Sydney.
Some of the chanting protesters carried placards reading "Behead all those who insult the Prophet."
Several streets, usually thronging with weekend shoppers, were blocked off by police as the protest grew. Police, many wearing anti-riot equipment and some on horseback, used dogs and chemical sprays as they tried to control the protest.
Reuters Television pictures showed one policeman with a head injury being led away by colleagues. Police later said six officers had been injured and eight protesters arrested. A spokesman for paramedics said there were no serious injuries.
A Muslim leader addressed the protesters in a park, calling for calm.
In Egypt, the interior minister said he would restore calm after a 35-year-old protester was killed and dozens of people were injured in clashes overnight.
The authorities closed the street leading to the U.S. Embassy where the demonstrators had spent four days throwing rocks and petrol bombs at police.
A Reuters reporter saw police push several young men into trucks. Two of the men looked bruised and one was stripped down to his underwear.
Police formed cordons on roads into Tahrir Square near the U.S. mission and plain-clothes officers wielding sticks frisked passers-by. The square, the focus of last year's popular uprising that overthrew President Hosni Mubarak, was strewn with garbage and a torched vehicle was towed away.
"Our presence here is to clear the square of people who are breaking the law," Interior Minister Ahmed Gamal el-Din said as he inspected the area. "We must preserve the square as a symbol of the revolution. That is the aim of our operation."
He said measures would be taken to ensure "those breaking the law" do not return.
The protesters said they wanted to expel the U.S. ambassador to punish Washington over the low-budget film. It portrays the Prophet Muhammad as a womanizer and religious fake. U.S. Secretary of State Hillary Clinton has called the film "disgusting and reprehensible."
Egypt's state news agency said 27 people were injured on Friday, which suggests more than 250 people have been hurt in the clashes since Tuesday, when protesters climbed the embassy's walls and tore down an American flag.
President Mohamed Morsi, an Islamist and Egypt's first freely elected leader, has to strike a delicate balance, fulfilling a pledge to protect the embassy of a major aid donor while delivering a robust line against the film to satisfy his Islamist backers.
In Sinai, militants attacked an international observer base close to the borders of Israel and Gaza, a witness and a security source said. Two Colombian soldiers were wounded, an official from the observer force said.
Many Muslims regard any depiction of the Prophet Muhammad as blasphemous. The film has provoked outrage across the Middle East and led to the storming of several U.S. missions in the region.
In Libya, authorities said they had made four arrests in the investigation into the attack on the U.S. Consulate in Benghazi on Tuesday that killed the U.S. ambassador and three other Americans.
Morsi has condemned the film, rejected violence and promised to protect diplomatic missions. His cabinet said Washington was not to blame for the film but urged the United States to take legal action against those insulting religion.
The United States has a large embassy in Cairo, partly because of a vast aid program that began after Egypt signed a peace deal with Israel in 1979. Washington gives $1.3 billion in aid a year to Egypt's army plus additional funds for government.
In Yemen, al Qaida urged Muslims on Saturday to step up protests and kill U.S. diplomats in Muslim countries and called the film denigrating Muhammad another chapter in the "crusader wars" against Islam.
"Whoever comes across America's ambassadors or emissaries should follow the example of Omar al-Mukhtar's descendants (Libyans), who killed the American ambassador," Yemen-based Al Qaeda in the Arabian Peninsula (AQAP) said.
"Let the step of kicking out the embassies be a step towards liberating Muslim countries from the American hegemony," it said in a statement posted on a website.
Reuters and The Associated Press contributed to this report.
More world stories from NBC News:
- Lebanese hope pope can 'bring peace' to the region
- Americans killed in US consulate attack honored at Andrews
- NBC's Jim Maceda answers questions about the Mideast protests
- 'Super typhoon' heading for Okinawa, South Korea
- Guatemalan eruption sparks massive evacuation order
- Photos: It's already Christmas for factories in China