Protesters occupy Department of Immigration offices on Lonsdale Street

Around 150 anti-detention centre protesters have caused chaos in the CBD.

The group, from Friends, Family and Feminists against detention, occupied the Department of Immigration offices on Lonsdale St late Thursday afternoon.

After being moved on by police, they then took over the intersection of Nicholson and Albert Streets.

It brought traffic to a standstill.

The group, which has attracted criticism for bringing young children to protests, returned to the Department of Immigration but police moved quickly to block them from entering the building.