Ukraine says one of its top regional security officers has been killed in a car explosion in the southeastern Ukrainian city of Mariupol.
The Ukrainian Security Service (SBU) cited its chief Vasyl Hrytsak as saying that Colonel Oleksandr Kharaberyush was killed in the car blast in the port city on the morning of March 31.
"The SBU will do all it can to locate and punish those involved," Hrytsak said.
Donetsk regional police chief Vyacheslav Abroskyn wrote on Facebook that an investigation has been launched into the car blast.
He wrote that investigators do not exclude that it was conducted by pro-Russian separatists who are controlling parts of Donetsk and Luhansk regions.
The government-controlled city of Mariupol is about 30 kilometers from the front line in the conflict between the Ukrainian Army and separatists that has killed more than 9,900 people in eastern Ukraine since April 2014.
On March 30, President Petro Poroshenko ordered the military to implement a cease-fire and weapons pullback beginning on April 1, but said he was "not very optimistic" that the separatists would abide by the truce agreement reached in Minsk the previous day.