Kenya Airways, known as KQ, said on Friday the staffers were arrested in its airport office in the capital, Kinshasa, over missing documentation for cargo that the airline had not accepted.

The cargo has been described as “valuable,” but its contents have not been disclosed.

“All efforts to explain to the military officers that KQ had not accepted the cargo because of incomplete documentation proved futile,” airline CEO Allan Kilavuka said in a statement.

He said the staffers' cell phones were seized and colleagues and embassy officials were only granted a few minutes with them.

The airline filed an application at the military court to have the staffers released and it was granted on Thursday, he said.

“Despite the court orders, the military intelligence unit is still holding them incommunicado,” the statement said.

The airline urged the Kenyan and Congolese governments to ensure the matter is resolved.

The two governments have not commented on the issue.

Kenya and Congo enjoy cordial relations, with Kenya participating in UN-backed peacekeeping missions in Congo.