EAST BERLIN -- The East German government threw open its borders Thursday and announced that its citizens now may travel freely to West Germany. Thousands of jubilant East Germans quickly tested the new policy by flocking to the crossing points in divided Berlin.

At Checkpoint Charlie, a major crossing point, a huge crowd gathered. As East Berliners in small groups made their way through the last barrier to West Berlin, the crowds on that side welcomed them with cheers and songs.

East German border guards, who obviously had no instructions on the new border policy, generally waved them through with puzzled smiles.

"I'm watching history being made," said one West Berlin bystander.

It was like New Year's Eve or a World Series victory celebration at this and other border crossings along the Berlin Wall. Late Thursday and early today, hundreds of people climbed atop the grim, grafitti-marred structure, long the symbol of the Iron Curtain dividing East and West. Some of them danced for joy there.

The new border policy was explained by Politburo member Guenter Schabowski, who told a news conference here that East Germans would "promptly" be given permits to go to West Germany. He said they could stay there if they wish, or return to East Germany.

"This means that the Berlin Wall has no more meaning," an East German official said Thursday night.

"The long-awaited day has arrived," declared West Berlin Mayor Walter Momper. "The Berlin Wall no longer divides Berlin."

Crowds swarmed through the streets long after midnight, auto horns blared, police sirens pierced the air, couples walked hand in hand toward the wall and people laughed and smiled, offering each other open wine and beer bottles.

Some East Germans arriving at border crossings at Invalidenstrasse and Prinzstrasse in their small, sputtering Trabant autos were almost prevented from entering by the crowds gathered to greet them. But they made their way through to West Berlin's bright lights.

Remarkably, many of the East Berliners returned later today to the drab, gray Eastern half of the city after sampling the bright lights of the West.

"I just wanted to take a look at the Kurfuerstendamm," said one young man in his 20s, as he returned from West Berlin's famous shopping district and headed back through the wall to East Berlin.

From their side, hundreds of West Berliners crossed into East Berlin, shouting, "The wall is gone, the wall is gone!"

A huge crowd gathered next to the Reichstag building at the Brandenburg Gate--the traditional scene of anti-wall demonstrations by West Berliners and the place where President John F. Kennedy uttered his famous line, "Ich bin ein Berliner."

Many people climbed atop the wall there. At 3 a.m., lights at the gate were still blazing as the crowd called out: "Open the gate!"

Beyond Berlin, as one analyst here put it: "This news is deeply significant. It changes the whole shape of Europe. It will take a while for the import of this to sink in."

In the euphoria of Thursday night, there were few formalities for those surging through the checkpoints in Berlin.

But beginning this morning, East Germans will be expected under the new open policy to get exit visas for travel abroad, whether permanent emigration or just a visit.

They will be allowed to go through any crossing point in the Berlin Wall except Checkpoint Charlie, which is reserved for foreigners and military personnel.