The Liberation Front of the Enclave of Cabinda (Flec) has used kidnappings of foreign workers and hit-and-run tactics against the remnants of one of Africa's most powerful armies in its struggle.
Flec is confident that it is close to winning an independent nation, which, with a population of 150,000 people and nearly pounds 1bn in annual revenues, could become an African Kuwait.
'We hope to win the fight this year but it has to be complete independence,' said Capt Bonga-Bonga, rebel commander of the southern region, said in an interview in the Flec-controlled village of Bofo, 30-miles north of Cabinda city.
After a distinguished career, first in the independence war against the Portuguese and later in the Angolan army, Capt Bonga-Bonga defected this year to Flec. 'I came to see that as a Cabindan, I had no choice but to fight for the independence of my country.'
The Cabindans base their independence claim on the Treaty of Simulambuco of 1885, which first linked Cabinda to Angola but recognised its special status. The treaty was part of Portugal's attempt to consolidate its empire during the Scramble for Africa.
Capt Bonga-Bonga's operational zone is near the Chevron/Gulf Oil complex at Malongo, where offshore drilling platforms produce nearly two-thirds of Angola's daily production of 500,000 barrels.
His troops - some as young as 13 - appeared well-disciplined. The morning after the interview, the guerrillas stopped a bus, ordered the Cabindan oil workers out, and burned the vehicle. A week before, they ambushed a truck carrying a senior police officer, Miguel Fernando Nzambi, killed him, and dumped his body into the Chiloango river.
Earlier this week, Capt Bonga- Bonga led a small unit to the Cabinda city jail and freed 69 prisoners, including seven Flec guerrillas, without firing a shot.
Despite the recent successes, many observers believe Flec's chances of winning full independence are slim.
Whatever government emerges in Luanda after the country's first multi-party elections on 29-30 September, it will not be able to afford to cut ties with the enclave. Oil provides Angola with more than 90 per cent of its foreign-exchange earnings, which are desperately needed to rebuild a nation devastated by 16 years of civil war and repeated South African invasions.
The Angolan President, Jose Eduardo dos Santos, has sought a negotiated solution to the conflict by promising greater autonomy and a greater share of the region's oil revenues, from 1 to 10 per cent.
But the only one of Flec's half a dozen factions with any military muscle, about 1,000 fighters, known as Flec-Fac and led by the Paris-based Nzita Tiago, has refused Mr Dos Santos' offer of talks. Jonas Savimbi, the leader of the opposition National Union for the Total Independence of Angola (Unita), has said that if he wins this month's elections he will make the Cabindans a better offer, but has not specified what that would entail.
But the Roman Catholic Bishop of Cabinda, Dom Paulinho Fernandes Madeca said: 'I have little hope for the dialogue because the men with the arms are not participating. If I ask my congregation to pray for autonomy, they would hate me. They are suffering like never before, and they see autonomy as a continuation of their current misery.'
Popular support for Flec appears overwhelming. Although the 2,807 square-mile-region is also rich in timber, phosphates and palm oil, poverty and illiteracy are widespread. Flec has called for a boycott of the forthcoming polls, and most of the 16,000 people who registered to vote were Angolan soldiers and government officials.
The army's morale is low. Last week several hundred troops went on the rampage in Cabinda and attempted to kill the provincial governor, Augusto da Silva Tomas. He escaped but at least nine civilians were murdered.
The unrest, fuelled by long terms of duty, scarce rations, and orders not to attack Flec positions, exploded after the rebels had killed two army officers the week before. 'They lost their friends and were very angry,' said Bishop Madeca. 'They saw all Cabindans as Flec, so if they could not get a Flec fighter, any Cabindan would do.'