A US embassy staff convoy faced gunfire in southeast Nigeria, a strike that left two employees and two cops dead.

Armed men also seized three people – a driver and two more cops – during the assault on Tuesday near Atani town in Nigeria’s Anambra State

A police spokesperson in Anambra, Ikenga Tochukwu, said a rescue and recovery effort was still ongoing.

“The criminals killed two of the Police Mobile Force members and two consulate staff, and burned their bodies and vehicles,” Ikenga said, adding the area had separatist violence.

It is not clear why the US embassy staff were in Anambra or how many people were in the convoy.

He also regretted the convoy decided to “enter the state without contacting the police in the area or any security agency”. Law enforcement, he said, got there only after the attackers fled.

US National Security Council spokesperson John Kirby briefly mentioned the incident at a White House press briefing on Tuesday, saying “it seems like a US convoy vehicle was assaulted”.

“What I can say is that no US citizens were involved and, so, there were no US citizens injured,” Kirby said.

The US Department of State later issued a statement saying its diplomatic staff were “working with Nigerian security services to investigate”.

“The security of our personnel is always paramount, and we take extensive precautions when organizing trips to the field,” it said.

“The assault happened along a main road at around 3:30pm local time (14:30 GMT). Police in Anambra have said they think separatists are behind the attack as part of a rising wave of violence.

Officials in the area often blame a separatist group called the Indigenous People of Biafra (IPOB), which has pushed to break away from Nigeria and create its own state.

In 2020, it set up a paramilitary group called the Eastern Security Network, supposedly to defend local farmers and people from crime — but Nigerian police have charged it with carrying out violent attacks.

IPOB has rejected any role in the violence. But tensions have increased since the arrest of the group’s founder Nnamdi Kanu, first in 2015 and again in 2021, after he had escaped bail and run away overseas for several years.”

Kanu had faced charges of treason and terrorism, which he denied. In October, an appeals court dismissed the seven-count charge of terrorism against Kanu, saying the trial court had no authority.

Separatists have long demanded a referendum to be held over the issue of independence in southeast Nigeria. But such issues have a troubled history: In 1967, the Republic of Biafra proclaimed independence, starting a three-year civil war in Nigeria that killed hundreds of thousands of people.

More recently, Nigerian President Muhammadu Buhari has opposed attempts to hold a referendum, saying the country’s unity was not up for debate. He is due to leave office at the end of this month after serving two four-year terms.

He will be replaced by President-elect Bola Tinubu of the All Progressives Congress.