BENGHAZI, Libya – After more than two months, Libya’s investigation into the attack on the U.S. Consulate in Benghazi appears to be nonexistent.

Key security commanders and witnesses say they were never questioned. No suspects have been named, and gunmen seen participating in the assault walk freely in the eastern Libyan city.

Hanging over the probe is a fear of reprisals from extremist militiamen.

Farag al-Fazani, a young commander of a Libyan security force commissioned to protect the U.S. post at the time of the Sept. 11 attack, says he sees militants he recognizes from that chaotic night. They recognize him too.

“I get death threats by phone (saying) you are an infidel and spilling your blood is permitted,” al-Fazani said. “No one can protect me. I see them and they know me.”

On Wednesday, the head of one of the city’s security agencies, National Security chief Col. Farag el-Dersi, was shot to death by three attackers as he headed home from work.

It is the latest in a string of killings of officials with no word on who is behind them, though there is no indication they are connected to the investigation.

U.S. and Libyan leaders have sworn to hunt down those who carried out the Sept. 11 assault, in which gunmen blasted their way into the consulate compound after nightfall and killed four Americans, including the U.S. ambassador to Libya, Chris Stevens.

Most officials and witnesses have blamed fighters from Ansar al-Shariah, an Islamic extremist militia in the city. But much remains unexplained – the attack’s motive, why Libyan security pulled back from the consulate and even what time the attack started, as well as the bigger questions of whether outside terror groups like al-Qaida had a hand.

The FBI, which sent a team to Tripoli to work with Libyan investigators, has said nothing about its findings so far.

From the Libyan side, there has been little sign of an investigation. Numerous senior security officials in the city approached by The Associated Press knew nothing about the probe, and none said they had been questioned by investigators.

Deputy Interior Minister Omar al-Khadrawi insisted the investigation was “going well” but could not say when it would be completed.

The confusion reflects the broader disarray of Libya’s state security. To keep a degree of peace, authorities rely on the numerous militias made up of tens of thousands of young Libyans who took up arms against Gadhafi.

Many militias are under the Interior Ministry’s Supreme Security Committee, giving them a veneer of state authority to handle security tasks police would normally perform, but they remain virtually independent, loyal to their own commanders and agendas.

Security officials are fearful of confronting the militias, which are far better armed than security forces. Ansar al-Shariah and its mother group, the Rafallah Sahati brigade, are among the strongest militias in Benghazi.