BERLIN -- German authorities allowed a popular rock festival to resume Saturday after a scare over people with suspected links to Islamic extremism prompted them to curtail its opening night. They said searches of the site turned up no suspicious objects.

A top security official said authorities had been obliged to put security first, hours after the Rock am Ring festival's organizer said his event was "paying the price" for officials' failure to prevent the December attack on a Christmas market in Berlin.

Authorities shut down and cleared thousands of fans from the three-day festival Friday evening, its opening night. Organizer Marek Lieberberg said 86,000 people left the site within 15 minutes without incident.

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Police found out that "at least one person of non-German origin on which there was police information in the area of terrorism had access" to secure areas at the event, Koblenz police chief Wolfgang Fromm told a news conference. The backstage passes didn't match those people's real names, he added.

That prompted officials to halt the festival at the Nuerburgring racing circuit in western Germany. Three people were arrested Friday night and their apartments were searched; all were released early Saturday, though they remain under investigation.

The German band Rammstein was the Friday night headliner, but hadn't yet started playing.

The festival grounds were clear by 9:30 p.m., about a half hour after people were told that they were going to have to leave.

It wasn't immediately clear how many fans were in attendance, but some 90,000 were expected by the end of the weekend at the event outside the western town of Nuerburg. Overall, some 85 bands were scheduled to play on four stages with Germany's Toten Hosen highlighting Saturday's list and California's System of a Down playing Sunday.

Following the recent attack in Manchester outside a concert, organizers had instituted strict security controls including body searches, while backpacks and bags were banned. Some 1,200 police were to be on hand for the event, in uniform and in plain clothes.

Germany has been on alert since a number of violent attacks last year, including the truck attack on a Berlin Christmas market that left 12 victims dead and dozens of others injured. The attack, carried out by a young Tunisian man who had been denied asylum in Germany, was claimed by the Islamic State group.