(Reuters) - The head of Ukraine's Russia-annexed Luhansk region said on Monday that Ukrainian shelling had damaged a fuel depot and triggered a fire in the town of Dovzhansk.

It was the third such Ukrainian attack on depots in the region this month.

Leonid Pasechnik, writing on the Telegram messaging app, said Ukrainian forces had used cluster bombs in the attack on the town, called Sverdlovsk, its Soviet-era name, by the Russia-installed local administration.

Pasechnik said emergency services were at the scene to keep nearby buildings safe from the fire in the town, which lies south of the region's main town, Luhansk.

It was the second Ukrainian strike on the region during the day, Pasechnik said.

There was no official Ukrainian comment on the attack on the fuel depot. Ukrainian war bloggers reported the strike and posted pictures of a large plume of smoke wafting skyward in what looked like a forested area.

Bloggers also reported an earlier strike in the region, with pictures of rubble outside a high-rise building.

Pasechnik reported strikes on oil storage depots earlier in May in Luhansk and in the town of Rovenky, near Dovzhansk.

(Reporting by Ron Popeski; Editing by Leslie Adler and Jonathan Oatis)