Germany's opposition leader has vowed to bar people from entering the country without proper papers and to step up deportations if he is elected as chancellor next month, as a knife attack by a rejected asylum-seeker spills over into an election campaign in which he is the front-runner.

Two people, including a 2-year-old boy, have been killed and three others were injured in a stabbing attack in Bavaria

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.