Knife attacker in Germany kills two

A knife attacker killed a two-year-old child and a man on Wednesday in a public park in Germany, where police arrested an Afghan man as the main suspect.

Chancellor Olaf Scholz condemned the "unbelievable act of terror" on a play school group that left three more people wounded, and demanded to know why the failed asylum-seeker had been able to stay in the country.

The latest in a series of deadly knife attacks in Germany threatened to fire a new debate over immigration ahead of a general election on February 23.

The adult victim -- a 41-year-old passerby -- died while trying to shield the children from a man slashing at them with a "kitchen knife" in the city of Aschaffenburg at around 11:45 am (1045 GMT), Bavaria's regional interior minister Joachim Herrmann said.

A two-year-old child of "Moroccan origin" was also killed, Herrmann told reporters at a press conference in Aschaffenburg.