German Chancellor Olaf Scholz condemned a deadly knife attack Wednesday as "an unbelievable act of terror" and demanded to know why the Afghan suspect had been able to stay in the country.

Friedrich Merz, currently leading in polls to become German chancellor, said Thursday if elected he will impose strict border controls.

Friedrich Merz says he will close Germany's borders to irregular migrants, including those with a right to protection.

A deadly knife attack on a kindergarten group in Germany, where an Afghan man was arrested at the scene, reignited a bitter immigration debate Thursday, a month before elections.

The conservative opposition leader tipped to lead Germany following next month's elections has promised far-reaching changes to border and asylum rules after a group of children were targeted in a deadly knife attack in Bavaria.

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