Berlin migrant centre was put in lockdown over the incident
One man was lift with knife injuries and barricaded himself in a room before threatening to kill himself.
The incident took place in a refugee centre in Treskow, which accomodates around 500 people.
Police were caled at around 10am local time today.
A 20-year-old resident had an argument several others before pulling out a knife and stabbing his 21-year-old brother, German media said.
Morgenpost added the attacker fled to a room.
Police blocked the area and tried to talk the man out of the room but he said he would call himself if they tried to force entry.
Thomas Neuendorf, a police officer, said: "In addition, the man threatened to kill anyone who was approaching him."
The attacker was later taken to hospital
Additioal police were called for and man eventually left the building.
Mr Neuendorf said: "The man voluntarily opened the door and handed himself in."
Celebrities pay tribute to Berlin Christmas market victims Tue, December 20, 2016
Celebrities pay tribute to those who were affected by the suspected terror attack on a Christmas market in Berlin.
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Celebrities pay tribute to the Christmas market victims in Berlin
The man was then taken to hospital. The police cleared the site around lunchtime.