KIEV, Ukraine – Two people were killed and about a dozen injured in a bomb explosion at a march Sunday in Ukraine's second-largest city marking the first anniversary of the ouster of president Viktor Yanukovych, the country's interior ministry said.
The Interior Ministry said the blast in the eastern city Kharkiv was due to an "unknown explosive device" and was being considered a terrorist act. A police officer was one of the dead, it said.
The violence comes as Ukraine continues to be riven by tension and bloodshed stemming from Yanukovych's fall a year ago. The Ukrainian parliament voted Feb. 22, 2014 to remove the Russia-friendly president, following months of increasingly violent protests in the capital, Kiev.
The Crimean peninsula, where residents largely regarded his downfall as a coup, was annexed by Russia a month later.
Then armed rebels opposed to the new authorities in Kiev took over large parts of two regions bordering Russia, setting off a war that has killed more than 5,600 people.
A peace plan envisioning a cease-fire and pullback of heavy weapons was signed 10 days ago, but cease-fire violations continue.
Ukraine plans to begin pulling back heavy weaponry from the front lines on Sunday in accordance with the peace plan, a military spokesman said. Ukrainian military spokesman Col. Andriy Lysenko told a briefing that the withdrawal was to begin, but did not give further details.
Rebel spokesman Eduard Basurin said the pullback from both sides is to take place between Sunday and March 7, but he did not specify whether rebels had made any moves yet. There was no immediate confirmation that the withdrawal had begun.
Both sides are to pull back their big guns and rockets from 15 to 43 miles away from the conflict line -- depending on the weapons' size -- creating a buffer zone of between 31-87 miles.
The buffer zone was a main element of a peace agreement worked out in marathon negotiations 10 days ago in Minsk, Belarus. It also calls for a full exchange of war captives. Late Saturday, 139 Ukrainian soldiers and 52 rebels were exchanged; it remains unclear how many prisoners in total are on each side and when other swaps might take place.
The cease-fire that was the first element of the Minsk plan was called into effect last Sunday.
Ukraine said Russia-backed separatists violated the cease-fire a dozen times during the night with artillery and rocket attacks and an attempt to storm a Ukrainian encampment. Lysenko said one serviceman was killed and three wounded over the past day.
Explosions were heard in the main rebel-held city Donetsk around dawn on Sunday and a rebel website says several buildings in the city were damaged by artillery.
Despite the reported violations, the level of firing appeared to be far lower than a week ago.
Among the attacks reported by the Ukrainian military was an attempt to storm positions in the village of Shyrokyne near the port city of Mariupol. That city remains of strategic concern to Ukraine because rebel seizure of it could help establish a land corridor between mainland Russia and the Russia-annexed Crimean peninsula.
Kharkiv, where the Sunday explosion took place, has considerable symbolic importance in the drama of Yanukovych's ouster. Part of the heavily industrialized east that had been his base of support, the city was the last place he was publicly seen in Ukraine before surfacing in exile in Russia.
He had fled Kiev the evening before, and in Kharkiv he gave a video interview bitterly likening the protesters against him to Nazis.
Opponents of the new Kiev regime seized some buildings in Kharkiv after his ouster, but unlike the neighboring Donetsk and Luhansk regions, the city settled down and remained in government control.
In Kiev, thousands participated in a march on Sunday commemorating the events of a year ago and honoring the more than 100 protesters who died during them. President Petro Poroshenko led the ceremony, joined by foreign representatives including the presidents of Poland, Lithuania, Germany, Georgia and the European Union.