A rhinoceros attacked and killed one zookeeper and severely injured another in its enclosure in the Austrian city of Salzburg, authorities said Tuesday.

The deadly attack occurred in the early morning hours, when a keeper was carrying out routine tasks in the Salzburg Zoo's rhino cage, police said in a statement.

"For reasons still unknown, a rhino attacked a 33-year-old woman zookeeper", who succumbed to her injuries on the spot, authorities said.

In an attempt to scare the animal away, another keeper, "a 34-year-old Austrian man, was also attacked... and seriously injured," police added.

The injured zookeeper was taken to a local hospital.

The attack, in which the keeper was probably trampled to death, happened shortly before 7:00 am (0500 GMT), according to the Austrian news agency APA.

The zoo will remain closed on Tuesday, it said on its Facebook page.

Situated in the gardens of the Hellbrunn Palace, the Salzburg Zoo houses 1,500 animals and attracts over 400,000 visitors per year.