A bomb blast that Ukrainian authorities have described as a terrorist act killed two people and injured five others in Kyiv, including lawmaker Ihor Mosiychuk of the nationalist opposition Radical Party.
The explosion occurred late on October 25 as Mosiychuk and several other people were leaving a local television station in Kyiv's Solomyanskiy district.
A spokeswoman for the Ukrainian Security Service (SBU), Olena Hitlyanska, wrote on Facebook on October 26 that the agency launched criminal proceedings into a suspected act of terrorism conducted by an organized terrorist group.
"Investigators are looking into all possible leads at this point; it has been established that unknown individuals blew up a motorcycle at the site where the lawmaker was passing by," Hitlyanska wrote.
The Interior Ministry said that one of the dead was a 30-year-old guard and special police officer.
The SBU's Hitlyanska was quoted as saying that the other person who was killed was a passerby she described as a local resident born in 1981.
Interior Ministry adviser Zoryan Shkiryak said earlier on Facebook that the explosion appeared to have been caused by a motorcycle parked near the exit of the TV station, and looked like "an attempt on somebody's life," and Mosiychuk's office said it was an attempt to assassinate him.
"There was an attempt on the life of Ihor Mosiychuk, a direct explosion when he was coming out of the building of Espreso TV6," the lawmaker's office said on Facebook.
Mosiychuk's Radical Party called the bombing an "assassination attempt."
"The assassination attempt against Mosiychuk is linked to his professional activities and political views," Radical Party leader Oleh Lyashko wrote on Facebook.
"Clearly, this is the work of our enemy's secret services," he said in an apparent reference to Russia, which seized Crimea from Ukraine in March 2014 and backs separatists in a war that has killed more than 10,000 people in eastern Ukraine since April 2014.
Speaking after surgery on October 26, Mosiychuk said he believed those behind the bomb blast are most likely in Russia and that it was carried out by agents of Russia in Kyiv. He said the hospital where he is being treated was cordoned off by guards.
Russian President Vladimir Putin's spokesman, Dmitry Peskov, dismissed accusations of Russian involvment as "baseless."
In a regular conference call with reporters, Peskov described the allegations were part of an "anti-Russian campaign that has unfortunately swept across Ukraine and Kyiv."
The blast was the latest of several incidents in the Ukrainian capital targeting politicians and a journalist.
Former Russian lawmaker Denis Voronenkov -- a Kremlin critic who had moved to Kyiv -- was gunned down in broad daylight in the Ukrainian capital in March.
A car bomb in July 2016 killed journalist Pavlo Sheremet, an independent Ukrayinska Pravda reporter whose work had been critical of both Russia and Ukraine.
The two earlier cases remain unsolved.
Mosiychuck's fellow Radical Party lawmaker Dmytro Linko said on Facebook: "Ihor has many fragmentation wounds and is being operated on, an aide is also seriously wounded."
Radical party lawmaker Evhen Deidei posted photos on his Facebook page that showed the burnt-out shell of a motorcycle in front of a blast-hit vehicle.
"Judging by the damage to the car and the shrapnel holes in the doors, the power of the explosion was pretty strong," he said.
With reporting by RFE/RL's Ukrainian Service, AFP, and Reuters