BERLIN (AP) - A fire at a zoo in western Germany killed a large number of animals in the early hours of the new year, authorities said.

They did not comment on local media reports that the fire was started by celebratory fireworks.

The Krefeld zoo near the Dutch border said the entire ape house burned down and all the animals inside are dead.

The DPA news agency, quoting officials, said the dead animals included chimpanzees, orangutans and two gorillas, as well as fruit bats and birds.

The zoo said the nearby Gorilla Garden didn't go up in flames, however. Gorilla Kidogo and his family are alive, the zoo wrote on Facebook early on Wednesday (Jan 1).

"An unfathomable tragedy hit us shortly after midnight." the zoo said. "Our ape building burned down to the foundation."

Both the zoo and the city said that they didn't know the cause of the fire and that police are investigating.

Officials would not confirm reports by local media that New Year's fireworks could have caused the blaze.

The zoo will remain closed on Wednesday.