The city of Donestsk in eastern Ukraine has been badly shelled over the weekend.
Witnesses said the strikes appeared to come from territory held by both government and rebel forces. It has been described as the worst fighting since a ceasefire agreement was signed in September.
Explosions could be seen at the airport where pro-Kyiv troops have been holed up, defending it against pro-Russian rebels since May.
Before the conflict, the city’s population was around a million, now it is less than half that. For those who do remain, daily life is a struggle.
Kyiv has accused Moscow of sending 32 tanks and truckloads of troops across the border in recent days. The claims were not substantiated and the Pentagon said they could not confirm them.
However at the weekend the Organisation for Security and Co-operation in Europe (OSCE) said it had detected unidentified convoys of trucks close to Donetsk. Rebel leaders said they belonged to them and they were moving them from their initial locations “for tactical reasons”.