The Kremlin said a ceasefire announced by Ukrainian President Petro Poroshenko is an ultimatum to pro-Russian separatists rather than an offer of peace, Russia's Interfax news agency has reported.
"This is not an invitation to peace and negotiations, but an ultimatum to militias in the southeast of Ukraine to lay down their arms," the Kremlin was quoted as saying.
It also claimed that a Russian checkpoint on the Ukrainian border had come under fire and demanded "an explanation and an apology" from Kiev.
More top news
There will be gales across Scotland and northern England this morning, but these will gradually ease through the afternoon.
An unnamed 14-year-old boy was taken into custody following the attack, Anderson County Coroner Greg Shore said.
Scientists hope to capture stunning images and valuable data in the final moments before its impact.