Russia has announced the delivery of new air defense missiles to Crimea, in a move scheduled before the latest tension with Ukraine.

The S-400 Triumph missile systems were earmarked for troops in Crimea last month, Russian media said at the time.

In a statement on August 12, the Russian military said that once the systems were set up, they would be used in exercises.

Russia, which annexed Crimea from Ukraine in 2014, said this week it had foiled a Ukraine sabotage mission.

The Kremlin accused Kiev of trying to send saboteurs into Crimea and reported the deaths of a soldier and a secret police officer in an operation to foil the alleged plot.

Denying the accusations, Ukraine placed its troops on alert along its de facto border with Crimea, and along its front line with Russian-backed rebels holding parts of Donetsk and Luhansk in the east.

A statement by Russia’s Southern Military District, which incorporates Crimea, said the missiles had been received by an air defense regiment in Crimea.

According to the statement, quoted by Russian news agencies, the missiles were successfully tested on the Kapustin Yar test range in southern Russia.

Russia’s Interfax news agency says t

The missiles are designed to hit airborne targets at a range of up to 249 miles and ballistic missiles at a range of up to 38 miles, flying at speeds of up to 3 miles per second.

The missiles are being installed in Crimea to protect Russia’s Hmeimim air base in Syria among other things, it adds.

In November 2015, Russia deployed S-400s at Hmeimim, after Turkey downed a Russian Su-24 bomber.

Ukraine’s envoy to the UN asked Russia on August 11 to prove its allegations, and said some 40,000 Russian troops were massed on the Crimea-Ukraine border.

His Russian counterpart told the UN Security Council of Moscow’s “concern and outrage” at the alleged incursions.

Russian state TV broadcast an apparent confession by a man named as Yevhen Panov, saying he was part of a Ukrainian defense ministry force sent into Crimea “to carry out acts of sabotage”.

Yevhen Panov said the group also included officers of Ukraine’s military intelligence.

Reports in Ukraine say Yevhen Panov is a former volunteer fighter who has more recently been associated with a charitable organization called Heroes of Ukraine.

Crimea was annexed by Russia after a majority of its mostly ethnic Russian population voted to secede in an unrecognized referendum on self-determination.

The annexation of Crimea was relatively bloodless, in sharp contrast to the ferocious fighting which followed in Donetsk and Luhansk.