*

Ukraine launches mass drone attack

*

At least seven missiles also fired at Russia

*

At least one oil refinery on fire after attack

*

Unconfirmed reports that armed group crossed border

(Recasts headline and lead)

By Guy Faulconbridge and Lidia Kelly

MOSCOW, March 12 (Reuters) - Ukraine pounded targets

across Russia on Tuesday with at least 25 drones and seven

missiles, Russia's defence ministry said, in a sweeping attack

that one local official said had left at least one refinery in

the world's second biggest oil exporter on fire.

Both sides have used drones to strike critical

infrastructure, military installations and troop concentrations

in their more than two-year war, with Kyiv hitting Russian

refineries and energy facilities in recent months.

Russia's defence ministry said it had downed 25

Ukrainian drones over Russian regions including Moscow,

Leningrad, Belgorod, Kursk, Bryansk, Tula and Oryol. Russian

local officials reported attacks on a slew of energy facilities.

"An attempt by the Kyiv regime to carry out a terrorist

attack using 25 drones on objects in the territory of the

Russian Federation was stopped," the defence ministry said in a

statement.

There was no immediate comment from Ukraine.

Gleb Nikitin, governor of the Nizhny Novgorod region,

reported a drone attack on a fuel refinery in the Kstovo

industrial zone.

"The Kstovo industrial zone, a fuel and energy complex

facility, was attacked by unmanned aerial vehicles," Nikitin

said on Telegram. A refinery was on fire, he said. He did not

name it.

State news agency RIA cited Russian Railways and

reported that a special train that puts out fires was battling a

blaze on the territory of Lukoil's refinery in Kstovo.

Lukoil did not immediately respond to a request for

comment.

Lukoil's NORSI refinery, Russia's fourth-largest

refinery, can usually process about 17 million metric tons of

oil per year (340,000 barrels per day).

Russian Telegram channels said a crude distillation unit

at the refinery had been damaged and was on fire. A catalytic

cracking unit at the plant was halted in January.

DRONES AND MISSILES

The Baza Telegram channel, which is close to Russian law

enforcement, said Lukoil's Nizhny Novgorod refinery had been hit

and showed pictures of a plume of black smoke rising into the

air and a major fire.

Reuters could not independently verify the report.

Russia's defence ministry said Ukraine had fired eight

RM-70 rockets and one Tochka-U missile at the Belgorod region

where some Russian war correspondents said there had also been

an attempt by armed groups to cross into Russian territory.

Oryol region's Governor Andrei Klychkov, said that

Ukraine had launched a drone attack at a fuel facility in the

region, while RIA cited emergency services as saying one

petroleum tank was on fire following the attack.

At least 17 people from high-rise buildings near the site of

the drone crash were reported to have been evacuated to a

temporary accommodation centre.

Officials in several regions continued to report drone

attacks after the defence ministry statement. No casualties were

reported in the attacks.

One drone flying towards Moscow had been downed over the

Ramensky district near the capital, Moscow Mayor Sergei Sobyanin

said on Telegram.