Libya has condemned a US military operation to capture the suspected leader of the deadly raid on a US diplomatic post in Benghazi in 2012.
The secret operation on 15 June near Benghazi to seize Ahmed Abu Khattala was an "infringement on Libya's sovereignty", Libyan diplomats said.
Washington earlier said Mr Abu Khattala was being held in a secure location outside Libya.
US ambassador Chris Stevens and three others were killed in the 2012 raid.
"The Libyan government condemns this regrettable infringement on Libya's sovereignty," Libyan foreign ministry spokesman Saeed Alaswad said on Wednesday.
Meanwhile, Justice Minister Salah al-Marghani said Tripoli had not been informed about the US operation in advance.
Mr Marghani also said the suspect must be returned to Libya and tried there because the local authorities had issued an arrest warrant against him. He provided no further details.
Earlier, Pentagon press secretary Rear Adm John Kirby said there were "no civilian casualties" related to the US operation.
"All US personnel involved in the operation have safely departed Libya," he added.
He refused to give further details about the US raid, only to say it happened "near Benghazi" and on Sunday afternoon US east coast time.
Ahmed Abu Khattala
- Native of Benghazi in eastern Libya
- Construction worker by trade
- Spent several years in Col Muammar Gaddafi's notorious Abu Salim prison in Tripoli
- Formed his own small militia during the anti-Gaddafi uprising
- Denies any links to al-Qaeda but has expressed admiration for it
- Also denies any role in the attack on the US embassy in 2012, but eyewitnesses report him being there
- US state department says he is a senior leader in Islamist group Ansar al-Sharia
After the announcement, President Barack Obama praised the courage and professionalism of the military, law enforcement and intelligence personnel who had tracked and captured Mr Abu Khattala, whom the US describes as a "key figure" in the attack.
"When Americans are attacked, no matter how long it takes we will find those responsible and we will bring them to justice," he said.
The FBI Director, James Comey, said his organisation would not stop searching until the other suspects were found.
Abu Khattala has been charged in a US federal court with killing a person in the course of an attack on a federal facility, providing material support to terrorists, and a firearms count, court records show.
Hillary Clinton, who was secretary of state at the time and been criticised by Republicans over the embassy's security arrangements, said questioning Abu Khatalla could shed some light on what happened and why.
On 11 September 2012, gunmen stormed the US consulate in Benghazi and set it on fire.
In addition to Mr Stevens, information technology specialist Sean Smith and security workers and ex-Navy Seals Tyrone Woods and Glen Doherty were killed.
The White House initially said the attack stemmed from anti-American protests over a crude video produced in the US that was deemed insulting to Islam.
Government investigators soon determined it was an organised attack planned by local militias.