The Ukrainian president has again accused Russian army officers of fighting alongside pro-Moscow separatists in the east of the country.
Petro Poroshenko said: "Russian staff officers are taking part in military operations against Ukrainian forces."
The war of words between Kiev and Moscow followed a weekend of intense fighting, in which Ukrainian forces say they inflicted heavy losses on pro-Russian rebels.
More top news
The driver stopped at the scene and the boy was taken to hospital, but he died on the way.
Sunday Times restaurant critic AA Gill has died at the age of 62, three weeks after revealing he had cancer.
The Oscar-winning actress has faced a backlash after telling a story about itching her "butt" on sacred Hawaiian rocks.