Britain has summoned Moscow's ambassador to London over reports of a Russian military incursion across its border with Ukraine, the Foreign Office said Friday.

Alexander Yakovenko was summoned "to clarify reports of Russian military incursion into Ukraine and continued buildup of equipment on border," the ministry said in a tweet.

Ukraine said on Friday it had destroyed part of a Russian military convoy that crossed onto its territory, sending tensions over the situation in the east of the country soaring.