Ukraine's military says "many" refugees have been killed in a rocket attack on a convoy in the east of the country. 

A spokesperson says women and children may be among the dead, and has blamed pro-Russian separatists.

However, rebels say they did not attack the convoy. They earlier claimed there was an exchange of artillery fire in the area.

Luhansk has been the centre of conflict between rebels and Ukrainian forces for months. Yesterday it was reported Ukrainian troops had regained partial control of the city, and are said to have raised the national flag over a city police station.

Meanwhile, Russia has said an aid convoy from Moscow has been cleared to enter Ukraine. The convoy has been stopped near the border since late last week due to Ukrainian and international fears that the vehicles could have also contained military materials or personnel from Russia.

The US has warned Russia that its actions in Ukraine are “extremely dangerous and provocative”. 

Ukraine President Petro Poroshenko claimed last week that government forces had destroyed part of a Russian military convoy it says crossed over its border.

Russia has denied any of its troops were in Ukraine and has reassured the Pentagon that there are no military personnel in the aid convoys.