A man armed with a knife is believed to be holding several members of staff at a job centre.
Specialist negotiators are at the scene at the Jobcentre Plus in Clifford Street in the Byker area of Newcastle after being called at 8am on Friday.
Nearby accommodation has been evacuated, while the metro station is closed.
In a statement, Northumbria Police said: “Officers have attended and found a man armed with a knife had entered the premises and it is believed that several members of staff are being held there. Several other staff members have left.”