The Ukrainian military said on Monday that four of its soldiers were killed and 15 wounded in fighting with pro-Russian rebels in the previous 24 hours.
A spokesman said the most intense fighting has been in western districts of rebel-held Donetsk in the east of the country.
The highest casualty figures in a fortnight came just before talks on a ceasefire were due to start.
The talks are being overseen by the Organisation for Security and Cooperation in Europe.
The February deal has been consistently violated however despite the OSCE presence.
According to news agency Reuters, 29 Ukrainian soldiers were killed and 175 wounded in July alone in the eastern territories.
Source: euronews On photo: Mariupol: Heavy combat fire rocked the outskirts of the strategic Ukrainian port city ofMariupol on Friday, AFP correspondents said, just hours before talks open on a possible ceasefire (AFP).