KIEV, Aug. 18 -- "Many people" were killed after a convoy of refugees was hit by heavy shelling in Ukraine's eastern Lugansk region on Monday, local media reported.

"Fighters attacked a convoy of refugees with mortar and rocket fire at 9:40 a.m. local time (0640 GMT) near the villages of Novoselovka and Khryashchevatoe," military spokesman Anatoly Proshyn was quoted by the online news portal Ukrainska Pravda as saying.

Following the attack, several cars from the column caught fire and "many people" in the vehicles were burned to death, Proshyn said, adding that the exact casualties were being verified.

However, Andrei Purgin, deputy prime minister of the self-proclaimed

Donetsk People's Republic, denied that insurgents were responsible for the deadly attack.

Ukrainian troops claimed on Sunday to have entered the rebel-held city of Lugansk and taken control of several public buildings that had been seized by the independence-seeking insurgents.

At least 2,000 people have been killed since the government troops launched an offensive against rebels in the eastern regions of Lugansk and Donetsk in mid-April.

The four-month-long conflict has also displaced hundreds of thousands civilians.