Russia says it arrests suspected Ukrainian agents; Kyiv says allegations trumped up

MOSCOW (Reuters) - Russia said on Thursday it had arrested three suspected Ukrainian intelligence agents, including one accused of planning to carry out an attack using two homemade bombs, allegations that Kyiv dismissed as trumped up.

The arrests come amid Ukrainian and western concerns over a buildup of Russian troops near Ukraine. Moscow denies planning an invasion and accuses Ukraine of building up its own forces in the east of the country.

Russia's FSB security service said in a statement that a suspected Ukrainian military intelligence officer had been arrested "red-handed" with two bombs that had been smuggled over the border.

It said two others, suspected agents of the Security Service of Ukraine (SBU), had sought to gather intelligence in Russia and film transport infrastructure and strategically important enterprises.

Ukraine's military intelligence service declined to comment. The SBU denied the Russian allegations.

"Such statements by the FSB should be viewed exclusively through the prism of hybrid war, in which ... propaganda and the spread of fakes play an important role," it said.

(Reporting by Anton Kolodyazhnyy in Moscow; additional reporting by Pavel Polityuk in Kyiv; writing by Tom Balmforth; Editing by Himani Sarkar and Peter Graff)