Jamsheed Marker told a closed-door briefing of the UN Security Council that Friday was an important milestone, diplomats said.

The envoy said that a total 195 out of 200 voter registration centres opened on Friday.

Four failed to open after anti-independence militia attacked a village 110km (70 miles) southwest of the main East Timor town of Dili on Thursday.

The fifth was inaccessible, Mr Marker said, without giving any details.

Violence

The run-up to the referendum has been marred by violence.

A spokesman for the UN mission in East Timor, Unamet, David Wimhurst, said Thursday's attack was regrettable, given the assurances from the Indonesian authorities that the security situation was improving.

Timorese opposing independence have demonstrated in Jakarta

He said the villagers had driven away the attackers, killing one man and wounding another. Four of the villagers were wounded.

UN Secretary-General Kofi Annan has told the Security Council that he will decide during the 20-day registration period whether the vote will go ahead as planned on 21 or 22 August.

The vote will determine whether East Timor's population of 800,000 wants moves towards complete independence or autonomy within Indonesia.

Indonesia invaded the territory in 1975 and annexed it a year later.

Registration abroad

BBC Jakarta Correspondent Jonathan Head: "Everything hinges on a change in attitude by the Indonesian authorities"

Voters must be 17 or over, and either born in East Timor or have a parent or spouse who was born there but they do not have to be currently living in the territory.

Registration stations opened on Friday in the Indonesian cities of Jakarta, Ujung Pandang, Surabaya, Denpasar and Yogyakarta, as well as in Australia, Mozambique, Macao, the United States, Switzerland and Portugal.

Unamet said it anticipated that one of its biggest problems will be registering an estimated 60,000 internally displaced people.