A protester throws a bottle toward a building of the Russian Embassy during a rally demanding the release of Ukrainian army pilot Nadezhda Savchenko by Russia, in Kiev, Ukraine, March 6, 2016. REUTERS/Gleb Garanich

Ukrainian protesters gathered outside the Russian Embassy in Kiev on Sunday to demand the release of a hunger-striking Ukrainian pilot being held captive by Russian authorities. Some protesters hurled stones and eggs at an embassy building, while others smashed car windows with baseball bats and burned the Russian flag, according to several news reports.

The protests erupted after the 34-year-old pilot, Nadezhda Savchenko, announced Thursday that she would begin a no-food and no-water hunger strike to protest delays in her trial. For many Ukrainians, Savchenko has become a national hero, as well as “a symbol of the country's resistance against Russia,” according to the BBC.

Savchenko has been detained since her capture in June 2014. Russian prosecutors say she directed an artillery strike that resulted in the deaths of two Russian television journalists in 2014. However, Savchenko and her attorneys have denied the charges, saying she had no part in the strike and was kidnapped by Russian separatists and smuggled into Russia before the strike even occurred.

“I am a prisoner of war and a hostage who has been abducted,” Savchenko told a judge in September.

On Sunday, several thousand supporters attended Savchenko rallies in several cities across Ukraine, including Kiev, Kharkov, and Odessa. In Kiev, protesters assembled in the iconic Maidan Square, many holding signs in support of the pilot. After the initial rally in Maidan Square, several hundred walked to the Russian embassy, where, according to a report from Agence France‑Presse, the protests became more aggressive. In fact, some protesters even created “a makeshift gallows...hanging an effigy of Russian President Vladimir Putin with a sign ‘murderer.’”

AFP noted that Ukrainian police opened up a “hooliganism” probe to investigate damage from the protests.

The U.S. State Department, meanwhile, recently called for Savchenko to be released immediately.

“The United States deplores her continued ill-treatment and is deeply concerned by reports of her deteriorating health,” Jen Psaki, a Department spokesperson, said in a statement on Feb. 25. “By any standard, Russia’s detention and treatment of Ms. Savchenko is unacceptable. We call on Russia to honor its commitments under the September 2014 Minsk agreements and the February 15 implementation plan by immediately releasing Nadiya Savchenko and all other Ukrainian hostages.”