At least four security personnel have been killed and 23 wounded in clashes with rebels in eastern Ukraine, authorities said Friday.
Four Ukrainian servicemen were killed Thursday overnight in clashes with rebels, Xinhua quoted National Security and Defence Council spokesman Andrei Lysenko as saying.
Lysenko said that fierce battles were still underway in ten towns and cities across Donetsk and Lugansk regions.
Earlier Thursday, government forces took control over a "significant part" of Lugansk city and continue encircling another rebel stronghold city of Donetsk.
Heavy fighting has been raging in Ukraine's restive east regions since mid-April, when the government troops launched offensive to regain control over rebel-seized cities and towns.
The conflict has claimed the lives of over 2,000 people and injured thousands of others.