Angry anti-US protests, including the storming of embassies, continued for a fourth day Friday from Indonesia to Morocco. Sparked by a rabidly anti-Islamic video posted on YouTube, the demonstrations have seen clashes with security forces leading to over a dozen deaths across several countries.

While the crude video produced by Christian right elements and obviously intended as a provocation has provided the trigger for these upheavals, underlying them is deep-seated anger over the wars and oppression inflicted on the region by American imperialism over decades.

The demonstrations began in Cairo on Tuesday. In Libya a protest at the US consulate in the eastern city of Benghazi turned into an armed attack by some 200 gunmen that killed the US ambassador and three other American personnel.

In response, the Obama administration dispatched a 50-member Marine special forces unit known as a Fleet Antiterrorism Security Team (FAST) and sent two US naval destroyers armed with tomahawk cruise missiles to the Libyan coast.

On Friday, Libyan authorities closed down the Benghazi airport for several hours after reporting that an increased number of US pilotless drones flying over the city had come under anti-aircraft fire from Libyan militias. Officials feared that the anti-aircraft fire might endanger civilian flights. The move sparked rumors that the US military was preparing to launch a raid on the area.

“With hi-tech weaponry and surveillance tools, the Pentagon and US spy services have turned their attention to finding those who laid siege to the American consulate in Benghazi on Tuesday, employing methods honed over years in Afghanistan, Pakistan, Yemen and elsewhere,” the AFP news agency reported.

Another FAST Marine special forces team has been dispatched to Yemen. On Friday, President Barack Obama submitted a letter to Congress formally announcing, in accordance with the War Powers Act, that he had dispatched troops “equipped for combat” to both countries. He said their mission was that of “protecting American citizens and property,” and that they “will remain in Libya and in Yemen until the security situation becomes such that they are no longer needed.”

Obama officiated Friday at a ceremony held in an Andrews Air Force Base hanger where the bodies of Ambassador J. Christopher Stevens and three other US personnel were returned from Libya. He repeated earlier vows of vengeance for the killings, declaring, “We will bring to justice those who took them from us. We will stand fast against the violence on our diplomatic missions… Justice will come to those who harm Americans.”

In her remarks at the ceremony, Secretary of State Hillary Clinton lectured the people of the Middle East not to “trade the tyranny of a dictator for the tyranny of a mob.” She didn’t mention that Washington had sought to keep all of these “tyrants” in power before they were toppled by the “mob.”

Some of the sharpest clashes on Friday occurred in Tunis, the capital of Tunisia, where the so-called Arab Spring began after the self-immolation of market vendor Mohammed Bouazizi in December 2010 triggered popular upheavals against social inequality and the oppressive rule of President Zine El Abidine Ben Ali.

At least three people were killed and another 28 wounded in clashes between security forces and thousands of demonstrators who stormed the US embassy in Tunis. Two of the wounded were said to be in critical condition. As elsewhere in the region, demonstrators included both Muslims who marched on the embassy directly from their mosques and large numbers of youth from surrounding working class neighborhoods.

In a chant that has been taken up by protesters in a number of countries, the Tunisians yelled, “Obama, Obama, we are all Osama,” referring to slain Al Qaeda leader Osama bin Laden.

The protesters breached the embassy’s walls, setting cars on fire in the parking lot, tearing down the US flag and replacing it with a black banner bearing the insignia, “There is no god but Allah and Muhammad is his messenger.” Across a highway from the embassy the demonstrators attacked an American school, looting it and setting it ablaze.

As police fired tear gas and live ammunition to disperse the protest, US security personnel evacuated the American ambassador from the embassy.

Yemen has also been the scene of violent clashes, reflecting mass hostility to Washington. The US has waged a drone killing campaign in the country while propping up a regime dominated by the family and henchmen of the former dictator Ali Abdullah Saleh, who was forced to resign by a mass uprising of workers, youth and tribesmen. Four people died in a siege of the US embassy in the capital of Sana’a on Thursday, and at least two more were killed in protests on Friday, as police fired live ammunition and employed water cannon to turn back another march on the embassy by angry protesters.

At least another three protesters were killed outside of the US embassy in Khartoum, Sudan on Friday, when thousands attempted to march on the building located in the city’s suburbs. Guards inside the building fired shots as the protesters climbed over security walls and ran up a black Islamic flag. Earlier, some 5,000 demonstrators stormed the neighboring German and British embassies. The German embassy was set ablaze and suffered serious damage. The ambassador and staff members had been evacuated.

The German broadcaster Deutsche Welle interviewed Florian Dähne, the representative of Germany's Friedrich Ebert Foundation in Sudan, who said that “the majority who took part in this violent escalation are frustrated people who live in a very dire social and economic situation. And they feel they somehow need to channel their frustration.”

Sudan’s foreign minister had earlier publicly criticized a German court ruling allowing an anti-Muslim protest by a small group of right-wingers.

In Egypt, where the protests began on Tuesday, demonstrators clashed throughout the day with security forces, which sealed off the roads to the US Embassy with large concrete blocks. Egyptian Army personnel worked to build a wall around the American compound. According to official reports, at least 224 people were injured during the demonstrations and scores arrested.

In the northern Lebanese city of Tripoli at least two protesters died in clashes with security forces. Demonstrators targeted US fast food outlets, which were looted and demolished.

There were substantial demonstrations elsewhere in predominantly Muslim countries from Africa to the Middle East and South Asia.

* In Bangladesh, over 10,000 took to the streets of Dhaka, with protesters burning US and Israeli flags.

* In Afghanistan, over 1,000 people demonstrated in the eastern city of Jalalabad, burning Obama in effigy.

* There were anti-American demonstrations in cities and towns across Iraq, which was occupied by US troops until the end of last year. The largest of the protests took place in the southern city of Basra, where thousands marched through the streets and burned US and Israeli flags.

* In the central Nigerian city of Plateau, thousands of youth gathered after Friday prayers at the city’s central mosque but were quickly dispersed by troops firing live rounds. “People said it was a peaceful demonstration, but as usual the military doesn’t believe anybody has the right to demonstrate,” said one of the protesters.

* Thousands of Palestinians gathered in Gaza City and the southern Gazan city of Rafah, chanting, “Death, death to America, death, death to Israel.” Several hundred who attempted to protest outside the Al-Aqsa mosque in Jerusalem were met by Israeli security forces, who fired tear gas and stun grenades, wounding several.

Large demonstrations were also reported in Pakistan, Indonesia and Malaysia.