Two U.S. mission employees missing since a Tuesday attack on a U.S. convoy in Nigeria's southeastern Anambra state, have been recovered alive and are under the protection of Nigerian authorities, the U.S. Embassy in Nigeria reported Friday.

According to the U.S. State Department, the two employees went missing Tuesday after unknown assailants attacked a convoy of two U.S. government vehicles in the Ogbaru local government area of Anambra state.

In a statement, the State Department said the convoy was carrying nine Nigerian nationals: five U.S. Embassy staffers and four members of Nigeria's police force. They were traveling in advance of a planned visit by mission personnel to a U.S.-funded flood response project in Anambra.

The assailants killed at least four members of the convoy.

In Friday's statement, the U.S. Embassy in Nigeria said its personnel were traveling to meet and accompany the two employees home.

The embassy said the motive for the attack is not clear, but they found no indications the convoy was targeted because of its U.S. connections.

The embassy said it continues to work with Nigerian security and law enforcement on this matter, to identify the victims previously found, and to bring to justice those responsible for the attack. They welcome any information the public might have regarding the attack.

Some information for this report was provided by Reuters and The Associated Press.