Nigerian troops used violence to suppress protests, while Shell resisted pressure to use its influence to improve the situation.
Nigerian troops reportedly fled, leaving British officers alone in the trenches.
Nigerian troops were also reported to be guarding key installations in the capital, Freetown.
The Nigerian troops were fighting to restore the President to power.
When Nigerian troops begin leaving Liberia in the thousands, as expected next month, it will be left without a properly trained national army.
The capital of the secessionist state was continuously being moved as Nigerian troops captured the older capitals.
When Nigerian troops finally reached the summit, fighting at close quarters ensued that cost both sides heavy casualties.
Washington has showered him with aid, including $10 million to reform the military and $50 million to train Nigerian troops for peacekeeping.
Biafra soon found itself at war with Nigerian federal troops, surrounded and cut off from reliable food supplies.
They were joined by 150 Nigerian troops later that month.