The Lithuanian translation of Underground, called Pogrindis, appeared in Lithuania in 2013. Here’s a link to an article about the novel’s background (in Lithuanian) as well as an interview with Tomas Donela, who has optioned the film rights. As for the novel itself, it’s available from the publisher at the link here.
For details of the book fair, see my blog post. Also her are a few more links to Lithuanian reviews and profiles: 1, 2, and a third one here. (If the last link doesn’t work, as mine is having trouble, you can find the review at Literatura ir Menas).
Here’s a Lithuanian television interview I did for an operation called “Alchemija.”