Its head American diplomacy Anthony Blinken condemned “in the strongest way” the attack they launched on Tuesday armed men against an American convoy in the southeast Nigeriakilling four people.

The two US government vehicles that were targeted were carrying five employees of the US embassy in Nigeria and four members of the Nigerian police. All nine were Nigerians. The attack took place on Tuesday afternoon in Ogbaru District of Anambra State, according to the local police.

According to Blinken, the embassy workers were going to an area where the US government is funding a flood relief project in order to prepare for a visit by US diplomats there.

“We don’t yet know the motive for the attack but we have no indication at this stage that it targeted the US (diplomatic) mission in Nigeria.”said the US Secretary of State.

Several separatist groups operate in this region of southeastern Nigeria and have recently intensified their attacks. They usually target the police and government buildings. Nigerian authorities attribute the attacks to the Movement of the Indigenous People of Biafra (Ipob), which they describe as “terrorist organisation”as well as its armed wing, the Eastern Security Network.