BERLIN (Reuters) - German police are carrying out a helicopter search for a man who stabbed two passers-by in the eastern city of Erfurt early on Monday morning, police said.

       The two victims, aged 45 and 68, were being treated in hospital. Police described the attacker as being in his twenties, with light hair and a scarred face. He spoke German, they added in a statement.

       Investigations are continuing into a knife attack in the town of Wuerzburg on Friday, in which three people were killed. Police are considering Islamist extremism as a motive in this case.

       (Reporting by Thomas Escritt, editing by Emma Thomasson)