( AFP ) - A crossing point symbolising the decades-old division of Cyprus opened to great fanfare in the heart of the capital Nicosia on Thursday, underscoring a new drive to reunify the Mediterranean island.
But some 12 hours later, the Greek Cypriots temporarily closed the crossing, claiming Turkish Cypriot police had been seen in the UN-controlled buffer zone in violation of a deal between the two sides.
The street was reopened two-and-a-half hours later.
Crowds massed in the morning as balloons were released into the sky to mark the opening of Ledra Street, a key thoroughfare in the world's last divided capital, sealed off since intercommunal violence erupted in 1963.
Nicosia Mayor Eleni Mavrou, a Greek Cypriot, described the move as a "first step" towards the reunification of the island, which has been partitioned along ethnic lines since Turkey invaded in 1974.
Mavrou and her north Nicosia counterpart, Cemal Bulutoglulari, had coffee and cake together on the Greek Cypriot side.
There was a carnival atmosphere as hundreds of people crossed through the passage in the commercial hub of Nicosia's old town over the UN-patrolled buffer zone that divides the Greek Cypriot and Turkish Cypriot communities.
In the Turkish-occupied north, hundreds of people gathered, beating drums and chanting songs of peace. Some wept with joy.
Celebrations continued into the night, with fireworks set off in the north.
Later however, government spokesman Stephanos Stephanou said "there was a violation of the agreement causing the checkpoint to temporarily close."
He was referring to police reports of an undisclosed number of uniformed Turkish Cypriot policemen having been seen in the buffer zone.
The crossing would reopen "once order is restored," he said.
It did re-open about two-and-a-half hours "after the situation was restored to what was agreed," Stephanou said. Nicosia police chief Kypros Michaelides said they had received assurances from the UN that it would not happen again.
The prime minister of the self-proclaimed Turkish Republic of Northern Cyprus, Ferdi Sabit Soyer, had dismissed the closure as "unacceptable." He told television in the occupied north there had been no violation.
"The Turkish Cypriot authorities are in touch with the UN to overcome the problem," he said.
The foreign minister of the TRNC Turgay Avci told Turkey's Anatolia news agency: "The area that they (the Greek Cypriot administration) are talking about is inside the borders of the TRNC."
"If there is a problem it can be discussed, but the TRNC's borders cannot be questioned, we will not allow it," he added.
UN spokesman Jose Diaz could not comment except to say his people were investigating the situation.
The reopening had been hailed as signalling a new climate of trust after several years of stalemate following the failure of a UN peace plan in 2004 that led a divided Cyprus to join the European Union that year.
In March, new Cypriot President Demetris Christofias and Turkish Cypriot leader Mehmet Ali Talat agreed to reopen Ledra Street and to resume full reunification talks in June.
"Today is a historic day. We are witnessing the overthrow of one of the obstacles to reunification," said Talat aide Ozdil Nami.
Speaking Thursday afternoon, as he left on a trip to London, Christofias expressed caution. But he added: "We consider it a significant element in our efforts, especially when it has to do with the need for daily contact between Greek and Turkish Cypriots."
As a next step, he called for "military disengagement across the full length of old Nicosia ... and certainly the opening of a crossing point at Limnitis" on the island's northwest coast.
The two sectors stand about 70 metres (yards) apart on what is known in Turkish as Lokmaci Street.
The barricades were among the first to be erected after intercommunal violence flared in 1963, leading to the arrival the following year of UN peacekeepers who have remained ever since.