Ukraine and pro-Russian separatists, in a gesture to shore up a tenuous ceasefire, agreed on Wednesday to strive for an end to all truce violations from next Tuesday, the OSCE and rebel representatives said.

The two sides agreed in February to a ceasefire between their forces in eastern Ukraine in parallel to a political process, including plans for local elections and establishment of a special self-management status for separatist-minded regions.

But sporadic clashes between the two forces, in which artillery and other weapons have been used and civilians, Ukrainian soldiers and separatists have been killed, have to undermined it.

Both sides have blamed the other for the violations.

"The three-sided 'contact group' considers it important to reach a solid ceasefire from the beginning of the next school year," Martin Saidik, an official for the Organization for Security and Cooperation in Europe, told reporters in Minsk, Belarus.

The so-called 'contact group' in which representatives of Ukraine, Russia and separatists groups take part, meets under the auspices of the OSCE.

"There was a proposal to end shelling from September 1. Today there is a hope that from September 1 we will succeed fully in ending the firing. At the moment all sides have expressed the intention of abiding by this idea," rebel leader Vladislav Deinego said.

Earlier on Wednesday, a Kiev military spokesman announced two Ukrainian soldiers had been killed in attacks by separatists in the previous 24 hours,

More than 6,500 people have been killed since the conflict erupted in eastern Ukraine in April last year after Russia annexed the Crimea in response to a pro-Moscow president being toppled by street protests in Kiev.