Musicians from Niger who were due to play a sold-out gig in Dublin on Friday night said they were "turned away" after they arrived at Dublin Port that morning.
Tuareg songwriter Mdou Moctar and his band's Belfast show - due to take place last night - has also been cancelled due to "visa issues".
In a post on Instagram, the group - also called Mdou Moctar - said they were "detained for eight hours" in Dublin.
Three of the band members are from Niger, the fourth is American.
The band said they had been told prior to arrival that their visas were the ones they required.
They had to cancel their performance at the Sugar Club in Dublin, which is part of their European Tour.
In the Instagram post, the band said that they "were very excited to play in Ireland for the first time" but could not due to "insurmountable obstacles".
The musicians said that after what they described as a "gruelling and traumatic day" they also cancelled their Belfast performance which was scheduled for last night at the Ulster Sports Club.
On Friday night, the Sugar Club tweeted that the Mdou Moctar gig was postponed "due to unforeseen circumstances we did everything to try and resolve" saying it was "devastated".
Announcing the postponement of the sell-out show in Belfast, promotor Strange Victory Presents said this had happened "due to visa issues", adding "10 months I’ve waited for this show, watching the audience for them build. Beyond gutted!"
The Department of Justice has advised that as the alleged incident took place at Dublin Port, it is a matter for gardaí.
In a statement, gardaí said they "cannot comment on named individuals".
However, they added: "A number of person were refused 'leave to land' at Dublin Port on the 8th April 2022 as they did not have the correct documentation to enter this jurisdiction.
"As per standard procedure they were required to depart from their point of entry on the next available transport in their circumstances."
