Several drones hit a critical infrastructure facility, while continued shelling has so far prevented a full assessment of the damage, Naftogaz said in a statement.
A UKRNAFTA gas station complex was also among the targeted sites.
Two female employees were injured in the attack and are receiving medical treatment, the company said. The station building and its equipment were completely destroyed.
“All targeted facilities are exclusively civilian infrastructure and have no connection to military objectives,” Naftogaz CEO Serhii Koretskyi said.
Emergency services are currently working at the sites as authorities continue assessing the consequences of the attack.
Earlier reports said 59-year-old Naftogaz employee Serhii Klymenko died in hospital after being injured during a Russian strike on Poltava Oblast on May 5.
Russia attacked the region with missiles and drones that day, killing four people, including two emergency responders and two Naftogaz gas production workers, local authorities said.
Russian forces also carried out a second strike on the gas production site after emergency crews arrived to respond to the initial attack. Ukraine’s State Emergency Service later reported that 23 rescuers were injured.
Ukraine’s railway operator also reported infrastructure damage caused by the attack.