Kiev forces clash with 'reconnaissance' group

Kiev - Ukraine said on Thursday its forces had clashed with a reconnaissance group that had entered its territory from the Russian-controlled Crimean peninsula.

The National Security and Defence Council said the fighting had flared on Wednesday in the Kherson region of Ukraine just north of Crimea, and accused the Russian military of "establishing positions" nearby in the peninsula.

The claims sparked fears that Moscow could be plotting an offensive towards the Black Sea peninsula after Kiev accused Russian troops of seizing territory along Ukraine's eastern border, some 450km.

Crimea, which Russia annexed in March in the face of Western outrage, straddles the Azov and Black seas and is connected by a narrow strip of land with Ukraine's Kherson region.

"On Wednesday evening border guards from... Kherson's Chervoniy Chaban [village] department engaged in a battle with a reconnaissance group from the territory of Crimea," a statement from the security council said.

"Border guards held their positions and forced the scouts to return to the peninsula," it said.

Earlier this week three Russian airforce helicopters ventured some 500m from Crimea into Ukrainian-held territory, Kiev said.

Ukrainian security spokesperson Andriy Lysenko also said the Russian military was "establishing positions" in the north of the peninsula.

"There is information being distributed among the local population of the possibility of military actions," he said on Wednesday.

Russia annexed Crimea in March after deploying troops to take over Ukrainian military bases and oversee a disputed referendum that saw residents vote to join Moscow rule.

Russia now fully controls the peninsula after the Ukrainian military and navy withdrew from the region without a fight.

Ukraine's Kherson region has not seen any fighting since the conflict between pro-Russian rebels and government forces erupted in eastern Ukraine in April.

Crimea is connected to Russia only by an overloaded ferry link, and a planned bridge is likely to take years and cost billions of dollars.

Kiev said on Thursday that Russian soldiers had taken the town of Novoazovsk, a city on the Azov sea close to the Russian border and some 450km to the east of Crimea.

Moscow swiftly denied that it has any troops inside eastern Ukraine, after rebel claims they had launched a counter-offensive after weeks of military advances by Kiev.

Crimea's vehemently pro-Kremlin deputy governor Rustam Temirgaliyev fuelled concerns that the fighting at the border could now spread west towards the peninsula.

Temirgaliyev wrote on his Facebook page on Thursday that after capturing Novoazovsk the rebel offensive would continue along the coast toward Crimea through the port cities of Mariupol and Berdyansk.