Police were called to the office at the intersection of Hillside Rd and Rankeillor St about 1.30pm after the brother of a client of the ministry assaulted the security guard, a police spokeswoman said.
``Fortunately, the guard was not injured,'' she said.
Following the assault, the offender and his brother fled the office.
``It is not clear what, if anything, preceded the assault but inquiries are ongoing, and police are working to locate the alleged offender,'' the spokeswoman said.
A ministry spokesman said the service centre was placed on restricted access following the incident.
``The Ministry of Social Development's South Dunedin service centre was briefly placed on restricted access this afternoon following an incident involving a security guard and a member of the public,'' he said.
``Police have been notified, and the service centre has resumed business as usual.''
