TRIPOLI, Libya — A powerful car bomb exploded Wednesday near Libya’s Foreign Ministry building in the heart of the eastern coastal city of Benghazi, security officials said, exactly one year after an attack there killed the U.S. ambassador and three other Americans.

The early morning blast targeted a building that once housed the U.S. Consulate under the rule of King Idris, who former Libyan dictator Moammar Gadhafi overthrew in a 1969 bloodless coup. The explosion caused no serious casualties, though several passers-by were slightly wounded, officials said.

The bomb blew out a side wall of the building, leaving desks, filing cabinets and computers strewn among the concrete rubble. It also damaged the Benghazi branch of the Libyan Central Bank along a major thoroughfare in the city.

No group immediately claimed responsibility for the attack, which also comes on the 12th anniversary of the Sept. 11, 2001, terror attacks in the U.S. The security officials spoke on condition of anonymity because they were not authorized to speak to journalists.

Gadhafi was killed after eight-month uprising that descended into a civil war in 2011. Since then, successive Libyan interim governments have failed to impose law and order. The country remains held hostage by unruly militia forces initially formed to fight Gadhafi. The militias, which have huge stockpiles of sophisticated weaponry, now threaten Libya’s nascent democracy.

Car bombs and drive-by shootings since the end the civil war routinely kill security officials in Benghazi, the birthplace of the uprising.

Tawfiq Breik, a lawmaker with the liberal-leaning National Forces Alliance, said that the attacks will continue as long as Libya lacks a strong national army and police.

“Even with so many officials assassinated, no one held accountable,” Breik said. “No one arrested. The state is disabled.”

The car bombing comes exactly one year after al-Qaida-linked militants stormed the U.S. mission in Benghazi and a nearby U.S. building, killing U.S. Ambassador Chris Stevens and three other Americans.

The attack sparked a wave of criticism toward President Barack Obama and his administration for its handling of the attack and its aftermath. The administration closed 19 diplomatic posts across the Muslim world for almost a week last month out of caution over a possible al-Qaida strike – likely in response to the Benghazi criticism.

On Aug. 9, Obama told reporters that the U.S. was still committed to capturing those who carried out the deadly consulate assault. Obama said his government has a sealed indictment naming some suspected of involvement. Officials said earlier that the Justice Department had filed under seal the first criminal charges as part of its investigation of the attack.

The Associated Press reported in May that American officials had identified five men who might be responsible for the attack. The suspects were not named publicly, but the FBI released photos of three of the five suspects, asking the public to provide more information about the men.

Some in the photographs are thought to be members of Ansar al-Shariah, the Libyan militia group whose fighters were seen near the consulate prior to the violence. Other witnesses reported seeing the leader of an Islamist militia group called Abu Obaida Bin Jarrah, whom U.S. officials told the AP is among the suspects in the sealed indictment. The leader has repeatedly denied being involved and says he abandoned the militia and now works in construction.

Earlier on HuffPost:

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  • U.S. President Barack Obama

    “The United States condemns in the strongest terms this outrageous and shocking attack. … Make no mistake: We will work with the Libyan government to bring to justice the killers who attacked our people. … We reject all efforts to denigrate the religious beliefs of others, but there is absolutely no justification for this type of senseless violence, none.” (AP Photo/Evan Vucci)

  • British Prime Minister David Cameron

    “This senseless attack ended the lives of people who had worked selflessly alongside Libyans during their darkest days. … We look to the new Libyan authorities to do all in their power, as they have pledged to do, to bring the killers to justice. Britain stands ready to assist Libya and the United States in that task. Above all, we will honor the memory of these dedicated people by continuing their work to help Libyans build a secure and free country.” (AP Photo/Ben Stansall, Pool)

  • Hamid Karzai

    “The Islamic Republic of Afghanistan strongly condemns this inhuman and insulting action (the film) and shows its strong hatred against this action. Insulting the messenger of Islam is to insult the values of 1.5 billion Muslims around the world. This insulting action will cause enmity and contrast between religions and cultures in the world and will be a strong punch to peace and harmony between humans.”(AP Photo/Ahmad Massoud / Xinhua, Pool)

  • Pakistan’s Foreign Ministry

    “Such abominable actions, synchronized with commemoration of atrocious events like 9/11, provoke hatred, discord and enmity within societies and between peoples of various faiths. The event has deeply hurt the feelings of the people of Pakistan and the Muslims all over the world.” (AP Photo/Brendan Smialowski, Pool)

  • Hezbollah

    The movie is an “immoral act that represents the highest levels of aggression against human rights that is represented by the respect of people’s beliefs. … The United Nations should issue laws that criminalize such acts similar to laws that criminalize anti-Semites.” (AP Photo/Bilal Hussein)

  • NATO Secretary-General Anders Fogh Rasmussen

    “It is important that the new Libya continues to move toward a peaceful, secure and democratic future.”(AP Photo/Shakh Aivazov, Pool)

  • Libyan interim President Mohammed el-Megarif

    “We extend our apology to America, the American people and the whole world.” (AP Photo)