In an interview with The Independent, Herminio da Silva da Costa, "chief of staff" of the self-styled Armed Forces for the Integration Struggle of East Timor, said his group would reject any result favouring independence from Indonesia, and that there would be a civil war if the United Nations Assistance Mission in East Timor (Unamet) attempted to enforce the result with international peace- keepers.
"If Unamet announces that the pro-independence side has won the ballot I promise it will be civil war again," he said in the offices of a pro- Indonesian group on the Dili seafront. "If the UN says they have won, then the pro-independence forces don't deserve to live any more, because it is not fair."
Monday's referendum produced a 98.6 per cent turn-out, and foreign observers predict an overwhelming vote for independence after 23 years of brutal occupation by Indonesia.
But Mr Da Costa said that a result supporting independence, rather than autonomy within Indonesia, would be proof that the UN had rigged the referendum results.
"My plan is to bring the problem to the UN and ask them to hold another ballot, this time organised by Indonesia. If they refuse, I would rather go to war to slaughter all the pro-independence people, because we will be sure that they have cheated."
The pro-Indonesian militias have made similar threats before, but Mr Da Costa's words are particularly alarming, coming as they do in an atmosphere of rising violence and panic in East Timor. There were gunfights between supporters and opponents of independence in the village of Hera, west of Dili. The mountain town of Gleno, where a UN convoy was prevented from leaving on Tuesday, was reported to be under control of the militias.
Yesterday the two flights leaving East Timor were filled with hundreds of evacuees, many expressing fears of a bloodbath after the announcement of the referendum result, expected early next week.
At Dili airport families with children and a large number of Indonesian journalists queued with boxes and suitcases to board a Hercules transporter plane specially laid on by the Indonesian military.
Dili has been rife with rumours of violence for weeks but, after the gun battle near the UN compound on Tuesday evening, many people are taking no chances. "A neighbour near the house where I'm staying said that the militia are planning to burn it down this afternoon," said Wardah Hamidy, an Indonesain radio journalist from Jakarta. "The militias think that journalists support the independence side, so many of us are leaving today."
The BBC team is to leave today, after its Jakarta-based correspondent, Jonathan Head, narrowly escaped serious injury after being kicked and beaten by a militiaman outside the UN compound on Tuesday. The number of dead from that attack has risen to three, all of them local people apparently supporting independence.
A small group of militiamen, armed with knives and a homemade pipe-gun, briefly entered the Hotel Turismo in Dili, where many foreign observers are staying, and kicked and terrorised a Canadian woman working for a non-government organisation. Militiamen tried to prevent a man, an Australian of Timorese descent, from boarding the plane, but the situation was defused by Australian and UN officials.
The Australian government has a rapid-reaction force in the city of Darwin ready to evacuate foreign nationals if the situation deteriorates further, but is hesitating to deploy for fear of increasing panic and offending Jakarta.
Five hundred Indonesian police officers flew in yesterday to reinforce some 15,000 security personnel already in the territory, but their presence will do little to restore confidence.
Elements in the Indonesain military are believed to be training and arming the militias, in defiance of the stated policy of the government, which repeatedly insist that it is doing its best to keep order in East Timor.
Under the UN's mandate, security in the province is entirely in the hands of the Indonesian police, who have consistently failed to arrest, disarm or act decisively against the militias. Foreigners in Dili have been reduced to bribing policemen to guard their hotels, offices and residences.
There is growing agreement in diplomatic circles that armed international peace-keepers will sooner or later have to be deployed to prevent the escalation of violence. Even after the announcement of a vote for independence, such a move would create uproar in Jakarta and raise the prospect of a head-on confrontation between Indonesia and the international community. "The UN is not neutral; they support the pro-independence side," Mr Da Costa said. "If UN security forces come here, that will create another conflict. If there is a conflict, we have the Indonesian military behind us."