By Aidan Lewis and Ayman al-Warfalli
MISRATA/BENGHAZI, Libya (Reuters) - A man seized by U.S. forces in Libya accused of involvement in an attack that killed the U.S. Ambassador in Benghazi in 2012 is a Syrian who had links to the suspected ringleader, Libyan military officials said on Tuesday.
U.S. special forces captured Mustafa al-Imam in the past few days and he is being transported to the United States, U.S. officials said on Monday, without giving more details.
Speaking on condition of anonymity, eastern-based military officials told Reuters Imam was believed to be a Syrian national aged between 35 and 40.
He was captured near Misrata, the country's third-largest city located some 190 km east of the capital Tripoli, said Mohammed al-Ghasri, spokesman of the defense ministry of the U.N.-backed government in Tripoli.
"He was caught near the city of Misrata after his movements had been monitored," Ghasri told Reuters in the first official statement of the Tripoli-based government.
When asked whether Libyan authorities had been present during the U.S. operation he only said: "Yes...(there) was coordination with the security agencies inside Misrata city." He declined to elaborate.
The man had been originally from eastern Libya but spent time in Misrata where he had roots while he also had been moving around, Ghasri added. "He did not live in Misrata."
Imam had previously lived in the Benghazi district of Laithi where he frequented the same Al-Awza'i mosque as suspected ringleader Ahmed Abu Khatallah who was snatched by U.S. forces in 2014, eastern military officials said.
U.S. prosecutors opened their case against Abu Khatallah this month.
Imam has been charged with "killing a person in the course of an attack on a federal facility" and providing "material support to terrorists resulting in death," the U.S. Justice Department said. He will appear before a federal judge in Washington when he arrives in the United States.
Laithi was an Islamist stronghold that saw some of the heaviest fighting in a battle for control of Benghazi that began in 2014.
In July, eastern-based military commander Khalifa Haftar announced victory in the campaign, which pitted his Libyan National Army (LNA) against Islamists and other opponents.
Libya has rival governments: one in the capital and another in the east allied to Haftar.
An eastern news agency backing the LNA published what it said was a picture of Imam standing in front of the Benghazi barracks of an armed group before it was taken by Haftar's forces.
The Benghazi attack, which killed Ambassador Christopher Stevens and three other Americans, was the topic of numerous congressional hearings, with Republican lawmakers critical of the way in which then-secretary of state Hillary Clinton handled the attack.
Libya has been mired in conflict since the 2011 overthrow of Muammar Gaddafi, with Islamist militants gaining ground as fighting between rival factions created a security void.
(Writing by Aidan Lewis and Ulf Laessing; Additional reporting by Ahmed Elumami in Tripoli; Editing by Ulf Laessing/Robin Pomeroy/Ken Ferris)