“I did wrong. I should have considered the situation more carefully,” Marin said in a television interview by public broadcaster Yle on Wednesday night.
Marin said she decided not to cut her night out short on Saturday after being told she had been exposed to the coronavirus the day before.
It emerged she had partied in the nightclub when a Finnish gossip magazine published a photo of her in the crowded venue.
Other members of her cabinet faced criticism too, as her economic Affairs Minister Mika Lintila attended a floorball match between Finland and Latvia on Sunday despite being advised to avoid contact with others, Helsingin Sanomat newspaper reported on Wednesday.
Defence Minister Antti Kaikkonen went to a dinner party on Saturday while Finance Minister Annika Saarikko and Science and Culture Minister Antti Kurvinen cancelled their attendance of the same event to avoid contacts, evening paper Ilta-Sanomat reported on Tuesday.
All three ministers were exposed on Friday at a meeting attended by Foreign Minister Pekka Haavisto, who on Saturday tested positive for Covid.
Marin said she was at a restaurant when she received a phone call from her state secretary informing her about the exposure.
“He said ministers would not be quarantined because they all have been vaccinated twice,” Marin wrote on Facebook, explaining why she continued socializing.
The Prime Minister’s office later said it had sent the exposed ministers two text messages on Saturday recommending that they avoid contact with other people.
Marin said she had left her official phone at home and instead relied on aides reaching her on her personal phone.
Marin has since taken two Covid tests that were negative. Lintila and Kaikkonen have also tested negative.
The Finnish Health Institute recommends avoiding social contact while waiting for COVID test results.