Workers MP Sam Lyomoki has been arrested and is being held at the Central police Station.
The workers called the rally to highlight their plight and failure by government to address key issues such as instituting a minimum wage.
A section of workers are today boycotting the International Labor Day celebrations being held in Gulu District.
The police remain heavily deployed at the square, with access to the grounds by members of the public limited.
The Police Spokesperson for Kampala Metropolitan region Ibin Senkumbi says the Constitutional Square is out of bounds to the public, advising the group to choose an alternative venue that does not pose any security threat.
The International Labor Day celebrations are being held under the theme ‘social dialogue for industrial harmony’.