Gunmen went on a shooting rampage in a shopping mall in the southern German city of Munich on Friday, killing many people, police said.

A Munich police spokeswoman said multiple people were killed or wounded.

"We believe we are dealing with a shooting rampage," the spokeswoman said.

ALSO READ: Employees still hiding outside in Munich Shootings

More than one gunman was believed to be involved and no one had been arrested, she said.

NTV television reported that German police special forces had arrived at the scene.

It was not immediately clear who carried out the attack, which took place a week after an ax-wielding teenager went on a rampage on a German train. Islamic State claimed responsibility for that attack.