A homemade bomb apparently hidden in a thin layer of snow exploded Sunday during a pro-Ukraine march in the eastern industrial city of Kharkiv, killing at least two people and wounding 11, authorities said.
Four suspected perpetrators of the attack were detained later in the day, Alexander Turchinov, secretary of the National Defense and Security Council told the UNIAN news agency. He said the detainees had been trained in the Russian town of Belgorod.
The bomb exploded shortly after 1 p.m. along the route where hundreds of people marched, many waving Ukrainian national flags, as part of a nationwide memorial to protesters who died a year ago during the so-called Maidan revolution in Kiev that ousted Russian-backed President Viktor Yanukovich, said Anton Gerashchenko, an Interior Ministry advisor.
Kharkiv is the capital of the Kharkiv region, which borders Russia as well as the Donetsk region of Ukraine, which for over 10 months has been the heart of an armed conflict between the Ukrainian government and pro-Russia separatists reportedly armed and aided by Russia.
One of the two declared dead at the scene of the bombing was a prominent local activist and the other a high-ranking police officer, Gerashchenko said. Five police officers were among the wounded, he said.
Dramatic video taken by a passerby and broadcast by TSN, a private television network, shows a column of people with flags and posters marching along the street, chanting and singing. An explosion shatters the scene, and people can be seen screaming, running and then trying to help the wounded.
"We have enough evidence to believe that this terrorist attack was organized and carried out by a group of terrorists armed and sponsored by Moscow," Gerashchenko said in an interview. "This cynical attack against peaceful marchers on the national mourning day clearly shows that regardless of the Minsk accords the Kremlin is set to continue to destabilize the situation in eastern Ukraine."
A cease-fire agreement was reached this month after talks in Minsk, Belarus, among the leaders of Germany, France, Russia and Ukraine. The accord called for a halt in hostilities and a withdrawal of heavy armaments and foreign fighters from the battle zone.
It has been repeatedly violated, and was again Sunday when separatists launched two tank attacks on the Ukrainian military near the seaport of Mariupol in eastern Ukraine, Andriy Lysenko, spokesman for the National Defense and Security Council, said at a briefing in Kiev. Both attacks were repelled, he said. No casualty figures were given.
More than 5,600 people have been killed in eastern Ukraine since the conflict broke out in April. More than 1 million people have fled the war zones for safe refuge in western Ukraine or across the eastern border with Russia.
"The explosion which these subhumans organized during a peaceful march in Kharkiv is yet another attempt to expand the territory of terrorism," Ukrainian President Petro Poroshenko said in televised remarks.