Russia's FSB says shell from Ukrainian territory destroys Russian border guard post

FILE PHOTO: Cars drive past the headquarters of the Federal Security Service (FSB) in central Moscow

MOSCOW (Reuters) -Russia's FSB security service said on Monday a shell fired from Ukrainian territory had completely destroyed a border guard post in Russia's Rostov region but caused no casualties.

Ukraine denied responsibility for the incident, which took place at a moment of extreme tension between the two countries as Russia continues to deny statements from the United States and its allies that it could invade Ukraine at any time.

"At 9:50 a.m. (0650 GMT) an unidentified projectile fired from Ukrainian territory completely destroyed a service point of the FSB border guards in the Rostov region, located about 150 metres away from the Russia-Ukraine border," the FSB said in a statement. "There are no casualties. Sappers are working there."

The RIA news agency shared video footage published by the FSB, which showed that a small outhouse had been torn apart. The footage did not show the projectile.

Ukraine said it had not shelled Russian territory. Its military has previously accused Russia of faking pictures of shells to make out they were Ukrainian, and said that mercenaries have arrived in separatist-held eastern Ukraine to stage provocations in collaboration with Russian special forces.

Shelling across the line dividing Ukrainian government forces and pro-Russian separatists in eastern Ukraine has intensified since last Thursday and diplomatic efforts to avert a military conflict between Russia and Ukraine have increased.

Russian-backed rebels seized a swathe of eastern Ukraine in 2014, the same year Russia annexed Crimea from Ukraine. Kyiv says that since then, some 15,000 people have been killed in the conflict in the east.

(Reporting by Maria Kiselyova; Writing by Alexander Marrow; Editing by Mark Trevelyan)