Benghazi bombing: Terrorists marking September 11?

A car bomb damaged a Libyan foreign ministry building in Benghazi on Wednesday, causing no known casualties on the first anniversary of the attack on the U.S. consulate in the country's second largest city.

Two years after the revolt that toppled Muammar Gaddafi, Libya is riven along regional and tribal lines and dogged by armed violence, leaving the central government struggling to curb the clout of rival militias and radical Islamists.

Local security officials said a car packed with explosives was left beside the ministry building where it detonated at dawn, badly damaging it and several other buildings in the centre of Benghazi. There were no reports of casualties.

A few hours before the Benghazi explosion, security forces defused a large bomb placed near the foreign ministry headquarters in the eastern Zawyat al Dahmani district of the capital Tripoli, the government said.

"Libyans cannot ignore the timing of this explosion. It's a clear message by the forces of terror that they do not want the state or the army to stand on its feet," Prime Minister Ali Zeidan told reporters.

Zeidan did not directly blame any group for the attack, but alluded to Islamist militants blamed for a spate of recent car bombs targeting security and army officers.

As well as militia violence, Zeidan's central government has also struggled to end strikes by oil workers and armed guards at oil installations that have paralyzed the North African state's crude production.

A year ago, four Americans including the U.S. ambassador to Libya were killed in an attack on the Benghazi consulate.

In Washington today, President Barack Obama observed a moment of silence and laid a wreath at the Pentagon to remember the 12th anniversary of the Sept. 11, 2001, attacks, events that still weigh heavily over the United States and over his tenure as commander in chief.

Obama acknowledged the decade of conflict that has followed Sept. 11. He paid tribute to the four Americans, including the U.S. ambassador, who were killed in an Islamist militant attack on a U.S. diplomatic compound in Benghazi, Libya, last Sept. 11. "We pray for all those who've stepped forward in those years of war, diplomats who serve in dangerous posts, as we saw this day last year in Benghazi," he said

Washington initially said the assault last year had grown out of anti-Western protests. But it later turned out Islamist militants were the perpetrators, marking the 11th anniversary of al Qaeda's Sept. 11 attacks on the United States.

Acting Interior Minister Al-Sadeeq Abdul Karim said the army and police were stepping up measures to stem the deterioration of security in Benghazi and other parts of the vast country.

Benghazi has seen a spike in car bombings and assassinations of army and security officers, many of whom served in Gaddafi's security contingents and then joined successor formations after the 2011 civil war.

Analysts say rebels and militants seeking revenge against former security officers who served under Gaddafi, and frustrated with the limited progress in bringing his ex-henchmen to justice, have sought to take the law into their hands. (Additional reporting by Mark Felsenthal in Washington; editing by Patrick Markey and Mark Heinrich)