A 21-year-old Syrian refugee killed a woman with a machete and injured two other people on Sunday before being arrested in the southern German city of Reutlingen, a police spokesman said.
The asylum-seeking Syrian man had been involved in previous incidents causing injuries to other people, he said. The spokesman had no immediate information on when the man arrived in Germany, or when the previous incidents took place.
The assailant was apparently acting alone, the police official said. "There is no danger to anyone else at this time," he told Reuters. No further details were immediately available.
It was the fourth act of violence against civilians in western Europe - and the third in southern Germany - in 10 days.
On Friday, a deranged 18-year-old Iranian-German who was obsessed with mass killings shot dead nine people in Munich before turning his gun on himself as police approached.
On July 18, a 17-year-old youth who had sought asylum in Germany was shot dead by police after wounding four people from Hong Kong, some of them severely, with an axe on a train and injuring a local resident near the city of Wuerzburg.
Four days before, a Tunisian delivery man drove a large truck into crowds celebrating Bastille Day in the French Riviera city of Nice, killing 84 people.
The Islamic State militant group claimed responsibility for both the Wuerzburg and Nice attacks. German police said the Munich gunman had no connection with militant Islam or the issue of refugees in Germany.