The car bomb that killed prominent Belarus-born journalist Pavel Sheremet in central Kiev on Wednesday was an improvised explosive device with a power equivalent to 400 to 600 grams of TNT, according to a statement by the Ukrainian Interior Ministry.
Sheremet, who wrote for the Ukrayinska Pravda newspaper and hosted a show on Radio Vesti, was killed when the bomb blew up the car he was driving. The newspaper reported that the car belonged to its editor-in-chief, Olena Prytula, but she was not in the vehicle.
The Organization for Security and Cooperation in Europe (OSCE), which has been independently monitoring the conflict between the Ukrainian military and pro-Russian separatists in eastern Ukraine for the past two years, condemned Sheremet's murder and called for a swift investigation.
"This morning's gruesome incident reminds us all that the safety situation for journalists in Ukraine must be addressed effectively and timely," OSCE media freedom representative Dunja Mijatovic said in a statement.
The explosion occurred outside a McDonald's restaurant at around 7:30 am (0430 GMT), state news agency Ukrinform reported.
Sheremet, 44, had previously been a television presenter in his native Belarus, but a conflict with the ruling regime saw him given a suspended sentence and he fled the country, living in Ukraine for about five years, Ukrayinska Pravda reported.
The newspaper's founder, Georgia-born investigative journalist Georgiy Gongadze, was abducted and murdered in 2000, and three former police officers were convicted for the crime eight years later. Gongadze's supporters accused the country's leadership of complicity in the killing.