Thousands of Muslim refugees have disappeared from camps and reception centres in Germany and are now unaccounted for, sparking all sorts of fear among Germans, including the possibility that they could be linking up with ISIS terrorists already in the country.

German press reports said thousands of refugees have left their accommodations on their own and are considered "on the run," according to WND.

Authorities said those who left their camps could be moving on their own to stay with family or friends already in Germany or in nearby countries.

They estimated that at least 7,000 people have left without registering with German processing centres.

Author-blogger Pamela Geller noted that in one camp alone, at least 580 refugees were reported to have disappeared.

The disappearances are continuing and spreading in other camps and reception centres, puzzling German authorities no end.

"It's become an epidemic," Geller said, noting that in the Brandenburg shelters alone, more than 6,000 migrants have left. "Where are they going? Who is sheltering these illegals, many with ties to ISIS?" she asked.

"Where are they hiding? Could they be connecting with sleeper cells?" Geller asked in her latest blog.

Such a high number of people unaccounted for is "completely unacceptable," German officials said.

"Is it any wonder that Europeans are scrambling for guns?" Geller wondered, recalling a report by WND earlier this week about gun shops running out of weapons to sell, particularly in Austria, as people seek to protect themselves from Islamic terrorists.

In the Brandenburg state capital of Potsdam several hundred migrants have been disappearing each week since the beginning of September, Ingo Decker, the spokesman of the city's Ministry of the Interior, told the German newspaper Die Welt.

On Wednesday alone, more than 600 people left the welcoming centre, Susan Fischer, the deputy ministry spokeswoman, reported to the newspaper.

According to official figures of the Brandenburg state government, more than 17,000 migrants from the Middle East and Africa have arrived since early September. About 7,800 are currently staying in cities and villages, about 2,700 people are still in the initial reception centres. That leaves at least 6,500 who have left and are AWOL – and that is just in one German state.

National authorities in Germany earlier required each of the cities and towns throughout the country to accept at least 4,000 migrants on short notice, but now authorities can't account for all of them.

Sources said majority of the nearly 1 million migrants who entered Germany are between 18 and 25 years old, many of them males.

Paul McGuire, an analyst who has appeared on Fox News and the History Channel and co-author of the new book, "The Babylon Code: Solving the Bible's Greatest End Times Mystery," warned that the missing migrants could reappear as terrorists attacking and destroying German villages and towns.

"There's no way they could be this stupid and let this many in. It has the look of something intentional," McGuire said. "I'm getting emails from people in Germany. They know this is being done on purpose, to destroy their villages and towns."

McGuire said what happened in France a few days after the Charlie Hebdo attack could be repeated in Germany. "They were sitting ducks, and the people of France were completely shocked," he said. "So they're setting the stage for another attack."