New Delhi: An international oil pipeline running through the Russian-backed separatist city of Lugansk in eastern Ukraine blew up on Friday, according to media reports.


Images of the blast show a fireball lighting up the night sky. During a sharp escalation in fighting which has redoubled hears that Russia is preparing to invade Ukraine, the incident took place, according to a report by news agency AFP. 


After a powerful explosion thundered in Lugansk, the Druzhba pipeline caught fire, according to a report by Russia's RIA Novosti state news agency. 


Emergency teams drove to the gas pipeline in Malaya Vergunka, after calls about the fire, the report said. 


The Druzhba pipeline, which runs from Russia to several points in eastern and central Europe, is the world's longest oil pipeline and one of the biggest oil pipeline networks in the world. 


Less than an hour after the blast that appeared to hit the pipeline, Russian state media reported a second blast, the AFP report said.


According to media reports, the explosions have been linked to a gas pipeline. 


The two blasts occurred in eastern Ukraine just hours after a car bomb saw the mass evacuation of 700,000 civilians from the region amid fears of a looming Russian attack in Ukrain, according to a report by the Daily Mail. 


The latest blasts occurred just afters an explosion, claimed to be a car bomb, rocked the city of Donetsk in Ukraine. 


In the past two days, the region around the city of Lugansk has witnessed some of its heaviest fighting since the beginning of the year.