The EU's lead spokesperson for foreign affairs and security policy, Peter Stano, said in a tweet Monday that the EU was "shocked about the tragic death of journalist Irina Slavina."
Slavina, whose real name was Irina Murakhtaeva, set herself on fire on Friday in the city of Nizhny Novgorod, 400 kilometers east of Moscow, according to a statement from the Russian Investigative Committee.
The Investigative Committee denied any link between the search of Slavina's apartment on the eve of her death and her act of self-immolation.
The 47-year-old was editor-in-chief of the small local news outlet Koza Press, which confirmed that she set herself on fire outside the regional department of the interior ministry in Nizhny Novgorod.
A graphic video showing a woman who appears to be Slavina setting herself on fire surfaced Friday on the Russian Telegram-based news outlet BAZA.
Stano said Slavina's death "needs to be thoroughly investigated also in light of pressures exerted on her for her work & activities."
Slavina's lawyer Evgeny Gubin told CNN after her death that she had been feeling the strain of a number of lawsuits filed against her. Gubin said he guessed that she had been "put on edge" by the "reports, court hearings, huge fines for what she didn't do."
In a Facebook post on Thursday night, Slavina said her apartment had been raided by officers from the Investigative Committee and Russian special forces police who seized flash drives, laptops, phones, and notebooks. This was followed by a post on Friday asking people "to blame the Russian Federation for my death."
Slavina had foreshadowed her death last summer when she questioned on Facebook whether if she arranged "an act of self-immolation near the FSB entrance or the city's prosecutor's office" it would "at least bring our state any closer to a bright future."