A leading human rights group says it has strong evidence Ukraine attacked populated areas of Donetsk with cluster bombs, banned by many other states, reports GHN based on BBC.
Human Rights Watch (HRW) accuses the army of using the deadly weapon, which scatters bomblets, to shell the rebel-held city earlier this month.
Ukrainian forces denied using "banned weapons" or shelling civilian areas.
Violence has continued in eastern Ukraine despite a ceasefire which came into place on 5 September.
At least 3,700 people have been killed in the conflict which broke out in April between Ukrainian forces and pro-Russian separatist rebels in the eastern regions of Donetsk and Luhansk.
Ukrainian President Petro Poroshenko agreed in a telephone conversation on Tuesday with his Russian counterpart, Vladimir Putin that the ceasefire agreed on 5 September should be fully observed, Mr Poroshenko's office said.
Meanwhile, the Ukrainian government has asked the EU for an extra loan of €2bn (£1.6bn; $2.5bn).
A source at the European Commission in Brussels told BBC News the money was not linked to Ukraine's ongoing gas debt talks with Russia, which are being brokered by the EU.
Russia is accused of using gas as a political tool against Ukraine.
In a separate development, a senior Polish official has alleged that Mr Putin suggested partitioning Ukraine with Poland six years ago in a conversation with Donald Tusk, who was Poland's prime minister at the time.
