The first team of police to respond to reports of an armed man in Mackay's CBD on Wednesday night, all junior officers, have been commended for their actions.

Detective Inspector Brendan Smith said police believed the 29-year-old Sarina man had no intention of harming any person, but was acting erratically due to mental health issues.

Police at Mackay CBD on May 31, following a man with two rifles reported walking through the city. Credit:Queensland Police Service

"At this point it appears it was a motivation around mental health issues," Inspector Smith said.

"We're happy that other than ... the rashness of his behaviour there was certainly no intention to harm any person."