Twelve people have been killed by a Russian drone strike near a company shuttle bus in eastern Ukraine, a regional official has said.

Preliminary information also found seven others were injured by the strike in the Pavlohrad district, regional military administration chief Oleksandr Ganzha wrote on Telegram.

Ganzha wrote: "We are investigating the details. An air alert is ongoing in the region."

Energy company DTEK said the vehicle had been transporting its workers from a mine in the region, calling it a targeted attack.

They had been travelling after a shift, the major provider said in a statement, and said 15 people had been killed in the attack.