Lithuanian artists on Thursday said they have placed a giant plastic bag over a fir tree in the capital Vilnius to warn against consumerism taking over the holiday season.

"This is a Christmas tree but we are using it as a piece of art to protest against the negative effects of hyper-consumerism," reads the message printed on the plastic.

Adorned with breathing masks, the art installation is located at the Vilnius railway station, which the city has turned into an alternative Christmas market this year. 

"People who do not feel comfortable at traditional Christmas markets or shopping malls are most welcome here," said Dominykas Ceckauskas, one of the artists behind the installation.

"Our message is that consumerism does huge harm to the environment during the holiday season," he told AFP.

The youth-oriented market also features train cars used as bars and restaurants, techno music instead of Christmas pop songs and local street artists, designers and second-hand merchants selling their wares. 

Vilnius mayor Remigijus Simasius said the event represents the "liberty, tolerance, and openness" of the city.