Munich police say the opening of the venue where Oktoberfest is taking place has been delayed because of possible connections to an explosion and fire at a house in the city, in which one person has died.
Mayor Dieter Reiter said the Theresienwiese would remain closed until at least 17:00 (15:00 GMT) on Wednesday because of a bomb threat.
A large-scale emergency operation is currently under way in Lerchenau in the north of Munich. Police said it was triggered by a fire in a single-family home, where residents also reported hearing an explosion.
Police are investigating possible links to other locations, including the festival site at Theresienwiese.
For this reason, the opening of the festival grounds has been delayed, said police.
Oktoberfest runs from 20 September until 5 October and has already attracted more than 3.5 million visitors, making it the world's biggest folk and beer festival.
Authorities investigating the fire in Lerchenau believe the residential building was deliberately set ablaze due to a family dispute.
The injured person who was found has since died. Another person is missing but is not believed to pose any danger, they added.
Booby traps were also found in the affected building. Special forces have been called in to defuse them.
Numerous emergency personnel are on site.