Berlin (AFP) - The German city of Braunschweig cancelled a planned carnival procession Sunday because of a "specific threat of an Islamist attack", police said.
The event, which was to begin at 1120 GMT, was called off two hours earlier following a tip by "reliable state security sources", police said in a statement.
"Police request all visitors not to go to the planned parade route or not to make the trip to Braunschweig in the first place," the statement said.
Police chief Michael Pientka told public broadcaster NDR there was no link between the cancellation and two fatal attacks in Copenhagen Saturday, which came little more than a month after Islamist attacks in Paris that left 17 people dead.
He later told a news conference that there had been no arrests, nor any explosives or weapons found.
Pientka said that unspecified security authorities had informed the police late Saturday about the threat and added that the information had been "very concrete in terms of the place and time" of a planned attack.
He said the region around Braunschweig had a well-known Islamist scene "but until now we did not believe it was of this type" to mount attacks.
Organisers said the annual event in Braunschweig, which has a more than 800-year tradition, was normally the biggest parade in northern Germany during February's Roman Catholic carnival season with up to 250,000 visitors expected.
More than 4,000 participants in fancy dress usually march and ride floats down a six-kilometre (four-mile) route through the city.
- Sad day -
The decision to call it off was taken by Mayor Ulrich Markurth and the parade's marshal, Gerhard Baller.
"This is a sad day for our city," Markurth told NDR. "The assessment of the police however left us with no other choice."
The Rose Monday processions, which mark the height of the carnival period, were scheduled to go ahead the next day in the western cities of Cologne, Duesseldorf and Mainz.
"We have no indication of threats," a spokesman for the regional interior ministry told news agency DPA.
"We assume everything will go ahead as planned."
Soon before the announcement, the federal interior ministry said it had not raised its threat level for Germany following the Danish attacks.
"We have no specific indications of planned attacks in Germany," a ministry spokeswoman told DPA.
Last month, Germany's biggest carnival procession, in Cologne, banned a float paying tribute to the slain cartoonists of French magazine Charlie Hebdo due to security fears.
The float design, selected in an online popular vote, featured a man dressed in black with an explosives belt and a drawn gun and a jester shoving a pencil down its barrel.
The carnival committee said that it backed the message of the float defending free speech and freedom of the press.
But it had received "messages from concerned locals which we take seriously", though organisers admitted there was "no indication" from the police of a credible terror threat.
Carnival in Germany is usually a potent mix of beer-soaked revelry and elaborately decorated floats that poke fun at political leaders.