KIEV, Jan. 27  -- Ukrainian troops and independence- seeking forces were locked in fierce fighting in eastern regions, killing at least 23 people in the past day, authorities said Tuesday.

The separarists had fired 120 times on the Ukrainian soldiers over the past 24 hours, with upsurge in fighting concentrating around the government-controlled Debaltsevo town, Ukraine's army spokesman Vladislav Seleznev said.

"As a result of combat actions, Ukraine lost nine servicemen, while 29 others have been wounded," Seleznev told reporters.

The government's battalion The North said at least 10 soldiers from the rebel forces were killed in clashes with the Ukrainian troops over the past day.

The insurgents have not commented on their casualties, while the rebel-run Novorossia news agency said that Ukrainian forces carried out 28 attacks on rebel positions in the past 24 hours.

The fighting was also raging in the rebel's main stronghold, the city of Donetsk, and its outskirts, killing at least four civilians and wounding 18 others, local authorities said.

There were no confirmed deaths in the neighboring Lugansk region, but four civilians were injured during a shelling in Shchastie town, the Lugansk regional administration said.

Tensions in eastern Ukraine flared up three weeks ago when the insurgents launched an offensive to seize the government- controlled airport in Donetsk, and pushed the operation toward other cities and towns in the conflict-torn regions. It is estimated that more than 5,000 people were killed in the violence in eastern Ukraine since April 2014.