The White House, meanwhile, said it was doing everything it could to protect its diplomats in Yemen, where witnesses reported that roads leading to embassy were closed down as the area was calm later in the evening.
Rioters chanting “O Messenger of Allah, O Mohammed...” launched a second assault on the American compound following an attack rebuffed by security forces earlier in the day.
President Abdurabuh Mansour Hadi apologized to U.S. President Barack Obama and to the American people for the acts of “a mob” and ordered an investigation into the attack.
"Those who are behind [this attack] are a mob that are not aware of the far-reaching plots of Zionist forces, especially those that made a film insulting the prophet,” Hadi said.
Some protesters said they saw three vehicles being torched by some of the demonstrators after they breached the compound through an unguarded security gate.
After being evicted from the complex on their first attempt, protesters retreated about 100 meters (330 yards) from the gate and gathered at a checkpoint where they chanted anti-Jewish slogans.
"O Jews, Khaybar, Khaybar. The army of Mohammed will return!” they chanted, referring to a 7th century CE war in the western Arabian Peninsula in which the Muslims were said to have defeated the Jews.
They then launched a second assault on the embassy compound, prompting police to fire on the crowd, killing one and wounding five others. Earlier in the day, six police officers and 13 protesters were wounded in clashes during the first attempted assault on the complex.
The attack on the U.S. Embassy in Yemen comes as violent demonstrations entered a third day at the U.S. Embassy in Cairo, where security forces have been firing tear gas cannisters to maintain control over the mobs.
Meanwhile, Americans mourned the deaths of U.S. Ambassador to Libya, Christopher Stevens, and three other American diplomats who were brutally murdered Tuesday night in a similar attack at the U.S. Consulate in Benghazi.
Protesters claimed the destruction of the consulate and torching of vehicles parked at the site was ignited by rage over an amateur satirical video produced in the United States that mocked the life of the Muslim Prophet Mohammed, founder of Islam, and included themes of sexuality, murder and violence.
But there is growing speculation that Al Qaeda terrorists were among the frenzied mob that carried out the murderous assault in Benghazi on Tuesday night, rather than simple demonstrators.
Moreover, there is increasing speculation that the continuing violence at other U.S. embassies around the region might signal a campaign of attacks previously promised by the international terrorist organization to mark the eleventh anniversary of its “9/11” attack on America.
Violence by hundreds of demonstrators has broken out at U.S. missions in Morocco, Sudan, Tunisia and Yemen, as well as in Egypt and Libya this week, all using their rage over the film, “Innocence of Muslims” as the excuse for the riots.
The obscure film, allegedly produced by California real estate developer Sam Bacile, whose identity is becoming increasingly mysterious, as he cannot be located. The video was reportedly released at least six months ago in English, but went unnoticed until it was translated into Arabic and a trailer posted on the YouTube website a few days prior to September 11. Clips of the film were also apparently broadcast on an Egyptian television channel over the weekend. Coptic Christians have since been accused of promoting the film, as has controversial Florida-based Christian Pastor Terry Jones, who in the past burned copies of the Qur'an.