SIX men detained over concerns about a possible attack on Berlin’s half-marathon have been released after investigators found no concrete evidence to back their initial suspicions, German officials said.

Berlin prosecutors said the six men, aged 18-21, were released after their investigation, including the evaluation of data stored on electronic devices, turned up insufficient evidence to keep them in custody.

The six were detained on Sunday, the day of the race, and daily newspaper Die Welt reported police foiled a plot to attack race spectators and participants with knives. Police said later on Sunday they had received vague indications of a possible attack plot and had taken action because of a generally high threat level, but had no “concrete indications” an attack was planned.

The investigation is still ongoing.

Meanwhile, a security official has said that the man who drove a van into a crowd in Munster on Saturday had no licence for the gun with which he then killed himself.

The 48-year-old German killed two people when he crashed into the crowd outside a popular bar in the western city on Saturday afternoon. Police said there was no indication of any political motive.