Looking for His glorious appearing! Titus 2:13

The planes targeted positions from where separatists, using high-powered Grad missiles, bombarded an army motorized brigade on Friday, killing 23 servicemen.

Warplanes also struck at targets near Donetsk, the east's main town where rebels have dug in, destroying a powerful fighter base near Dzerzhinsk, Andriy Lysenko, a spokesman for the "anti-terrorist operation" said.

"According to preliminary assessment, Ukrainian pilots ... killed about 500 (rebel) fighters and damaged two armored transporters," Lysenko told journalists.

In an earlier air attack on a base near Perevalsk, north of Donetsk, two tanks, 10 armored vehicles and "about 500" rebel fighters were destroyed, he said.

Rebel representatives, quoted by Russian news agencies, denied they suffered big losses and said the Ukrainians were using outdated intelligence on where separatist forces were deployed.

"There were no volunteers (rebels) where the Ukrainian aviation was active yesterday," said a spokeswoman for the Luhansk-based separatists, referring to the Peravalsk attack.