Nine police officers were injured during a LGBT "March for Equality" in Kiev on Saturday, after right-wing counter protesters attacked the event, according to a press release from the Ukrainian Ministry of Internal Affairs.
Police deployed more than 2,000 officers to protect the event, which was canceled last year because the police said they would not protect participants. One of the injured officers took a "shrapnel wound" to the neck, according to officials.
This video shows police detaining and unmasking attackers.
The Ministry of Internal Affairs said 25 people were arrested for "illegal actions" during the march.
Ukrainian President Petro Poroshenko committed to protecting the marchers on Friday.
Kiev Mayor Vitaly Klitschko had said the march should be canceled because it could "inflame hatred" while much of the Eastern portion of the country is still controlled by Russian-backed separatist rebels.
The EU has made protection of LGBT rights a key test for Ukraine and the two other post-Soviet states currently seeking to deepen ties with the bloc. Several other countries in Eastern Europe have gone through similarly violent clashes over LGBT rights protests as they have tried to win EU membership. Brussels dropped LGBT anti-discrimination requirements last year to allow Ukraine to sign a major EU agreement, but expects Kiev to pass them on its path to a visa-free travel regime.
Poroshenko swept to office last year on a pro-EU platform in special elections held after his Russian-backed predecessor Viktor Yanukovych fled the country. Yanukovych abruptly backed out of the EU deal under pressure from Moscow in 2013, sparking mass protests that eventually cost him his power.
Right-wing forces have attacked previous attempts to hold LGBT events in Kiev, and groups including the nationalist Right Sector had reportedly pledged to disrupt the Saturday march if it were allowed to proceed.
Despite the clashes, LGBT activists appear to consider the march a success.
"We went out for our rights, and the freaks ran to meet us, to crush us," Dmitry Pikakchi, an activist with the LGBT group Fulcrum, wrote on his Facebook page. "There were many emotions and feelings. But that doesn't matter now...We did it."
Activists stressed that this was a march about human rights, not a pride parade.
"The LGBT community has nothing to celebrate," an activist named Anna Sharygina said, quoted in a write-up posted on the Gay Alliance Ukraine's website. "This is a March for Equality, not a parade. Today we speak about LGBT right as human rights. For example, in the labor law we constantly have problems. If [employers] find out about people's sexual orientation, they fire them."
The question of employment protections is especially sensitive. The European Union requires states seeking closer ties to the EU to pass a law that makes it illegal for employers to discriminate on the basis of sexual orientation. (Gender identity is not part of this requirement.) The EU delayed imposing this requirement on Ukraine during the politically tenuous period following last year's confrontation with Russia, but it is likely a hurdle that Ukraine will have to clear if it moves forward with the process that would allow Ukrainians to travel in the EU without visas.
Sharygina also referenced a recent alleged hate crime in which a gay man was beaten in the town of Kharkiv. "The most painful thing is hate crimes against the LGBT community... Is this really not about human rights?"
Activists are collecting money to defray the costs of the injured officers' medical treatment.
Anna Sharygina was quoted in an article posted on the Gay Alliance Ukraine's website. An earlier version of this post said she wrote the article