(Reuters) - Ukraine's military launched a "mass" drone attack on southern Russia's Krasnodar region, killing one person and targeting an oil refinery, among other sites, local officials said.

A worker in a boiler room was killed when drone debris crashed into it, regional governor Veniamin Kondratyev wrote on the Telegram messaging app.

A drone also damaged an office building at an oil refinery, the governor added.

Emergency officials, writing on the Telegram messaging app, said three municipalities came under attack. Fragments from one drone fell on a guest house in Temriuk district, but its residents were evacuated and there were no injuries.

Emergency crews were working at the sites of the attacks.

(Reporting by Ron Popeski; Editing by Sandra Maler and Himani Sarkar)