US officials announced that a former Navy SEAL was among the four Americans killed during the attack on the US consulate in Benghazi, Libya on Tuesday.
CBS News reported 42-year-old Glen Doherty was part of the security team protecting US Ambassador Christopher Stevens, who was also killed.
US Attorney General Eric Holder said that the FBI has opened an investigation into the deaths, the Associated Press reported. Agents will be sent to the consulate in Libya with a team of protection to look for evidence, according to CBS.
Foreign Service Officer Sean Smith, a former member of the Air Force, has been identified as the third victim, while the identity of the fourth American killed has not yet been released, according to CBS News.
Smith had worked as an information management officer posted in Brussels, Baghdad and Pretoria over the past 10 years.
More from GlobalPost: Libya arrests 4 suspects in US consulate attacks in Benghazi
As GlobalPost wrote previously, an unnamed Libyan official told the Wall Street Journal that Libyan authorities have arrested four suspects in connection with the attacks, with a larger group of people still under surveillance as part of an investigation.
A senior Libyan official told CBS the attack was an organized "two-part operation by heavily armed militants that included a precisely timed raid on a secret safe house just as Libyan and US security forces arrived to rescue the consulate staff."