"I just got informed about that here before coming out," Kirby said during the press briefing. "It does look like a US convoy of vehicles was attacked. What I can tell you is that no US citizens were involved and therefore there were no US citizens hurt."
However, Kirby said that the US government is aware that there were some casualties as a result of the attack.
"But I don't want to get too far ahead of where we are right now. It just happened and the State Department is looking into this," Kirby added.
The US Department of State later released a statement saying its diplomatic staff were "working with Nigerian security services to investigate".
A US diplomatic convoy was attacked by gunmen in south-east Nigeria’s Anambra state and resulted in killing four people and abducting three others, Anambra's police spokesperson Ikenga Tochukwu revealed.
"The hoodlums murdered two of the Police Mobile Force operatives and two staff of the Consulate, and set their bodies ablaze and their vehicles," Tochukwu said.
He also lamented that the convoy opted to "enter the state without recourse to the police in the area or any security agency", noting that the area was known for separatist activities.
Officials in the region often point to the operations of a separatist group called the Indigenous People of Biafra (IPOB), which has spearheaded a movement to secede from Nigeria in favor of a republic of its own.