Greek and Turkish Cypriot leaders today began historic talks aimed at reuniting the island before it enters the European Union on May 1.

The UN envoy, Alvaro de Soto, greeted President Tassos Papadopoulos of Greek Cyprus and Rauf Denktash, his Turkish Cypriot counterpart, at Nicosia's abandoned airport in the buffer zone dividing the island.

A bombed out passenger jet stood in a field near the airport and buildings were pockmarked with bullet holes from 1974, the year supporters of union with Greece staged a coup and the Turkish army invaded, events which split the island in two.

But there are fears that extremists could try and disrupt the UN-sponsored talks. Hours before the start of the talks, a small bomb exploded at the home of Mehmet Ali Talat, the prime minister of the self-declared Turkish Cypriot state. A neighbour was slightly injured by flying glass.

"In this process, there may be some people who are disturbed by the two communities coming closer, but such acts will not make us return from this path," Mr Talat told reporters outside his home.

UN police from Australia and Ireland patrolled the abandoned airport as the talks got under way.

The United States and the EU have put pressure on Turkey and Greece to push their ethnic communities on the island to reach a settlement by May 1.

Cyprus then joins the EU, either as a united country or one with UN peacekeepers patrolling the buffer zone.

For Turkey, Cyprus' entry as a split country could be a disaster for its own EU bid. Turkey has 40,000 troops on the north of the island and EU leaders have made it clear that those soldiers could be considered as occupying EU territory after May 1.

The last round of talks collapsed in April when Mr Denktash rejected the reunification plan proposed by Kofi Annan, the UN secretary general.

Mr Denktash said that uniting the Turkish Cypriot north with the Greek Cypriot south would lead to Greek Cypriot domination. The south, with a population of 600,000, has three times as many people as the north and about five times the per capita income.

But the EU accession has become increasingly popular in northern Cyprus, which is internationally isolated as well as poorer, and enthusiasm for membership has put intense pressure on Mr Denktash since his fellow hardliners lost control of parliament in the January elections.

At the same time, Mr Denktash faces pressure from Turkey. "It is just suicidal for any [Turkish] political force to appear as if they are standing between Turkey and the EU," Soner Cagaptay, an analyst with the Washington Institute for Near East Policy, told the Associated Press.

The plan calls for a single state with Greek and Turkish Cypriot federal regions, linked through a weak central government. But many details, such as how many Turkish troops would remain on the island and how many refugees could return to their homes, are sharply contested.

According to the timetable for the talks, the two sides have five weeks to work out an agreement using the Annan plan as their basis.

If they fail, Greece and Turkish leaders will enter the talks. And if that fails, Mr Annan has the right to fill in the blanks and put the agreement to a referendum on each side of the island on April 21.

Newspapers on both sides of the island held out the hope that the talks, which have strict deadlines, could succeed after decades of failures.

"The historic process is beginning today," headlined Kibris, the largest newspaper on the Turkish side.

"Beginning of the end," said the Greek Cypriot paper Politis."