After blocking a nine-day government drive to occupy the central highlands city of Huambo, Mr Savimbi's political stronghold, rebel troops have launched attacks on the north-western town of Soyo, the source of one-third of Angola's 500,000 barrels-a-day production of oil, which earns 90 per cent of the country's foreign exchange. US and European oil companies have evacuated expatriate workers.
Unita already controls Angola's lucrative diamond fields, and had repeatedly threatened to target the oil fields. Unita soldiers have returned to the bush in the northern enclave of Cabinda, producer of two-thirds of the oil, the Angolan news agency reported.
Also under increasing threat is the central port of Lobito, where police and armed civilians drove Unita troops out of town. Rebel forces have regrouped 40 miles north-east of Lobito in the Canjela region and dynamited the bridge on the main road from Lobito to Luanda, the capital.
The latest fighting, sparked by Mr Savimbi's refusal to accept his defeat in the UN-supervised presidential and parliamentary elections last September, has seen Unita driven out of the cities but maintaining its hold on the central highlands and the northern border with Zaire.
The pro-government Jornal de Angola newspaper yesterday said that white mercenaries and Zairean army forces were helping Unita's war effort in the north. The Dos Santos government has confirmed the fall of Cuito Cuanavale, whose airport would make possible air force bombing runs on Unita's far-southern bush headquarters at Jamba.
The UN verification mission (Unavem) has pulled out of 41 of 67 observer locations. 'Our strength has been steadily falling,' Margaret Anstee, the special UN envoy, said yesterday. 'This is a war situation.'